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Sample records for leon fine sand

  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. Fine sand in motion: the influence of interstitial air

    NARCIS (Netherlands)

    Homan, T.A.M.

    2013-01-01

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

  3. Simulation study of cutting sugarcane using fine sand abrasive waterjet

    Directory of Open Access Journals (Sweden)

    Somjet Thanomputra

    2016-03-01

    Full Text Available Current rotary blade choppers for sugarcane harvesting have the disadvantage of becoming clogged with leaves/cane around the rotating blades causing them to hit the ground and rocks that result in rapid blade wear and tear. Dull blades require repeated cane cutting attempts causing damage to the cane and increasing the cutting force and energy requirements. Thus, the search for alternative, non-contact, cutting options such as waterjet (WJ cutting has been undertaken. The results indicated that WJ cutting has potential but weaknesses have also been reported. Hence, this study explored the use of abrasive fine sand (AWJ to overcome the weaknesses of the pure WJ cutting application. Using the Hoogstrate model and a MATLAB program, AWJ cutting simulation was performed using an orifice and nozzle diameter combination of 0.25 and 0.76 mm at 360 MPa water pressure, respectively, which produced a water flow rate of 1.6 L/min and a power input of 15 kW. Other parameters used in the test included: 80 mesh fine river sand abrasive materials, a specific cutting energy of 8.7 × 10−3 J/mm3 and a fitted cutting efficiency of 0.35. The experimental results revealed that the system was able to cut sugarcane stalks completely at a much farther standoff distance by reducing the traverse speed. The study also showed that cutting sugarcane of 30 and 120 mm diameters would require a traverse speed of 4.4 km/h and 1.1 km/h, respectively. The results implied that limitations should be set for sugarcane thickness for the optimum traverse speed and a standoff distance should be set to no more than 210 mm with a minimum traverse speed of 0.6 km/h.

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

    NARCIS (Netherlands)

    Yao, Y.

    2016-01-01

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

  5. Use of Crushed Granite Fine as Replacement to River Sand in Concrete Production

    Directory of Open Access Journals (Sweden)

    Manasseh JOEL

    2010-12-01

    Full Text Available The suitability of Crushed granite fine (CGF to replace river sand in concrete production for use in rigid pavement was investigated. Slump, compressive and indirect tensile strength tests were performed on fresh and hardened concrete.28 days Peak compressive and indirect tensile strength values of 40.70N/mm2 and 2.30N/mm2 respectively was obtained, with the partial replacement of river sand with 20% CGF, as against values of 35.00N/mm2 and 1.75N/mm2, obtained with the use of river sand as fine aggregate. Based on economic analysis and results of tests, river sand replaced with 20% CGF is recommended for use in the production of concrete for use in rigid pavement. Conservation of river sand in addition to better ways of disposing wastes from the quarry sites are some of the merits of using CGF.

  6. Performance comparison of sand and fine sawdust vermifilters in treating concentrated grey water for urban poor.

    Science.gov (United States)

    Adugna, Amare T; Andrianisa, Harinaivo A; Konate, Yacouba; Ndiaye, Awa; Maiga, Amadou H

    2015-01-01

    A comparative investigation was conducted for 10 months with sand and fine sawdust vermifilters and a control unit to treat concentrated grey water generated from a poor urban household in Ouagadougou, Burkina Faso. Each of the filters was made up of cylindrical DN200-PVC pipes and filled with 10 cm of gravel at the bottom. On top of the gravel layer, filter 1 (fully sand, F1) was completed with 40 cm of sand and 10 cm of fine sawdust, filter 2 (partially sand, F2) with 20 cm of sand and 30 cm of fine sawdust, respectively, and filter 3 (fully sawdust, F3) and 4 (control, F4) with 50 cm of fine sawdust only. Two hundred Eudrilus eugeniae earthworms were inoculated in each of the vermifilters. The vermifiltration system was supplied with grey water four times per day at a hydraulic loading rate of 64 L/m(2)/day on a batch basis. The removal efficiencies of biological oxygen demand, total chemical oxygen demand, and dissolved chemical oxygen demand (dCOD) by the vermifilters were 25-30% higher than the control, but little differences were observed in terms of total suspended solids and coliform removal efficiencies. Though there was no significant difference in the performance of the three vermifilters (p > 0.05), except for dCOD removal efficiency, the lifespan of F2 and F3 was longer than that of F1. Therefore, fine sawdust can substitute sand as a filter medium in vermifilters.

  7. Methanogens and sulfate-reducing bacteria in oil sands fine tailings waste

    Energy Technology Data Exchange (ETDEWEB)

    Holowenko, F. M.; Fedorak, P. M. [Alberta Univ., Edmonton, AB (Canada). Dept. of Biological Sciences; MacKinnon, M. D. [Syncrude Canada Ltd, Edmonton, AB (Canada)

    2000-10-01

    In addition to adding to greenhouse gas emissions, the production of methane in the fine tailings zone of Syncrude Canada's lease near Fort McMurray, Alberta, threatens to affect the performance of the settling basin and impact on reclamation plans. Methanogenic as well as sulfur reducing bacteria have been found within the fine tailings zone of various oil sands waste settling basins. This paper presents a description of the methanogenic population in the fine tailings and evaluates the effects of sulfate additions and prolonged sample storage on methanogenesis with serum bottle microcosms. Methane yield values were determined from total methane produced in batch microcosms monitored for over a year. Results showed that at present two to five per cent of the fine tailings volume is present as methane. Methanogenesis was found to be inhibited by sulfate addition which stimulated bacterial competition for available substrate. 47 refs., 3 tabs., 4 figs.

  8. Microbial activity influences pore water recovery from oil sands mature fine tailings

    Energy Technology Data Exchange (ETDEWEB)

    Foght, J.; Bressier, D.; Cardenas, M.; Fedorak, P.; Guigard, S.; Gupta, R.; Siddique, T. [Alberta Univ., Edmonton, AB (Canada)

    2010-07-01

    Studies have shown that natural anaerobic microbial activity in mature fine tailings (MFT) produces methane and accelerates settling of fines, accompanied by release of pore water. However, the microbial activity is limited by low concentrations of microbial substrates in the MFT. In this study, MFT was amended with additional substrates such as agricultural waste streams or microbial products such as carbon dioxide. The objective was to increase the densification rate and accelerate pore water recovery compared to unamended or inactivated control conditions. This biological phenomenon was observed using MFT from different oil sand operators. An overview of the research results was presented and the potential for accelerating microbial activity to increase water recovery from MFT was discussed. Dewatering of oil sands tailings deposited into settling basins was shown to be important from both an environmental and industrial standpoint. figs.

  9. Experimental investigations on mode II fracture of concrete with crushed granite stone fine aggregate replacing sand

    Directory of Open Access Journals (Sweden)

    Kanchi Balaji Rao

    2012-02-01

    Full Text Available With a view to implement sustainability concepts (namely, use of locally available materials and industrial by-products in the concrete construction industry, the possibility of use of crushed stone fine aggregate as replacement to river sand is explored in this paper. Towards this, tests have been carried out on concrete cubes and concrete cylinders. The effect of variation in percentage replacement of river sand with crushed stone fine aggregate on the mechanical properties is studied. In order to popularize the locally available material for the construction of shear critical concrete structures (viz. flat slabs, foundation of heavy structures, the Mode - II fracture behavior of the considered concrete is studied using DCN (Double Central Notched specimens with different notch to depth, (a/w, ratios of 0.3, 0.4, 0.5 and 0.6. For each (a/w ratio five different percentage replacements (viz. 0, 25, 50, 75 and 100% are considered. The study indicates that both cube compressive strength and split tensile strength increases with the increase in percentage replacement up to 50% and then gradually decreases. A similar observation was made with respect to the Mode - II fracture energy also. It is noted that the strengths of concrete even with 100% replacement are higher than the concrete with 0% replacement suggesting that the locally available crushed stone fine aggregate can be considered as an alternative to the river sand.

  10. Application of toxicity testing in the evaluation of reclamation options for oil sands fine tails

    International Nuclear Information System (INIS)

    Nelson, L.R.; MacKinnon, M.; Gulley, J.R.

    1993-01-01

    The hot water process for the extraction of bitumen from oil sands leads to the production of large volumes of wastewater and the formation of a large inventory of fine clay tailings. This fine tailings material and its associated water are acutely toxic to various aquatic test organisms during bioassays. An overview is presented of toxicity testing at Syncrude and Suncor, the application of toxicity testing to fine tailings management, and the role in reclamation planning. The main acutely toxic component of the tailings is the polar organic acid fraction, specifically naphthanates. These naphthanates are readily degraded biologically by indigenous microbial populations. Toxicity testing is aimed at assessing the degree of both acute and chronic toxicity and the long term potential for the input of toxins into the environment from various proposed reclamation measures. 28 refs., 6 figs., 2 tabs

  11. Coupling Solute and Fine Particle Transport with Sand Bed Morphodynamics within a Field Experiment

    Science.gov (United States)

    Phillips, C. B.; Ortiz, C. P.; Schumer, R.; Jerolmack, D. J.; Packman, A. I.

    2017-12-01

    Fine suspended particles are typically considered to pass through streams and rivers as wash load without interacting with the bed, however experiments have demonstrated that hyporheic flow causes advective exchange of fine particles with the stream bed, yielding accumulation of fine particle deposits within the bed. Ultimately, understanding river morphodynamics and ecosystem dynamics requires coupling both fine particle and solute transport with bed morphodynamics. To better understand the coupling between these processes we analyze a novel dataset from a controlled field experiment conducted on Clear Run, a 2nd order sand bed stream located within the North Carolina coastal plain. Data include concentrations of continuously injected conservative solutes and fine particulate tracers measured at various depths within the stream bed, overhead time lapse images of bed forms, stream discharge, and geomorphological surveys of the stream. We use image analysis of bed morphodynamics to assess exchange, retention, and remobilization of solutes and fine particles during constant discharge and a short duration experimental flood. From the images, we extract a time series of bedform elevations and scour depths for the duration of the experiment. The high-resolution timeseries of bed elevation enables us to assess coupling of bed morphodynamics with both the solute and fine particle flux during steady state mobile bedforms prior to the flood and to changing bedforms during the flood. These data allow the application of a stochastic modeling framework relating bed elevation fluctuations to fine particle residence times. This combined experimental and modeling approach ultimately informs our ability to predict not only the fate of fine particulate matter but also associated nutrient and carbon dynamics within streams and rivers.

  12. Effect of class F fly ash on fine sand compaction through soil stabilization.

    Science.gov (United States)

    Mahvash, Siavash; López-Querol, Susana; Bahadori-Jahromi, Ali

    2017-03-01

    This paper presents the results of an experimental investigation carried out to evaluate the effect of fly ash (FA) on fine sand compaction and its suitability as a material for embankments. The literature review demonstrates the lack of research on stabilization of sandy material using FA. The study is concerned with the role of FA content in stabilized soil physical characteristics. The main aim of this paper is to determine the optimum quantity of FA content for stabilization of this type of soil. This is achieved through particle size distribution and compaction (standard proctor) tests. The sand was stabilized with three proportions of FA (5%, 10% and 15%) and constant cement content of 3% was used as an activator. For better comparison, the sand was also stabilized by 3% cement only so that the effect of FA could be observed more clearly. The results were in line with the literature for other types of soil, i.e. as the % of FA increases, reduction in maximum dry density and higher optimum moisture content were observed.

  13. Microorganisms in oil sands tailings ponds influence the properties and behaviour of mature fine tailings

    Energy Technology Data Exchange (ETDEWEB)

    Bressler, D.; Cardenas, M.; Fedorak, P.M.; Guigard, S.; Gupta, R.; Siddique, T.; Foght, J. [Alberta Univ., Edmonton, AB (Canada)

    2010-07-01

    Large numbers of microorganisms are present in the mature fine tailings produced during oil sands operations. Many different types of microbes grow in communities that compete and cooperate. Most of the microorganisms are anaerobic, and include sulfate-reducing bacteria, nitrate-reducing bacteria, iron-reducing bacteria, fermenters, and methanogens. The microbes produce approximately 40 million litres of greenhouse gases (GHGs), methane (CH{sub 4}) and carbon dioxide (CO{sub 2}). All tailings ponds are microbiologically different. The gases are produced by microbial waste products and have been observed to degrade fugitive naphtha in fresh tailings at a Syncrude oil sands facility. At a Shell-Albian Sands facility, the microbes degraded into trisodium citrate. The microbes can aid in the settling of tailings. Agricultural byproducts have been added to tailings in order to demonstrate methane production. However, flow through systems are required to accelerate the biodensification of tailings ponds, and further studies are needed to ensure that the quality of recovered water is maintained for re-use. Various microbe degradation processes and models were presented. tabs., figs.

  14. The chemical and biological evolution of mature fine tailings in oil sands end-pit lakes

    International Nuclear Information System (INIS)

    Chen, M.; Weisener, C.; Ciborowski, J.

    2010-01-01

    This presentation described an innovative bench-scale technique to characterize oil sand tailings and their impact on sediment oxygen demand (SOD) for future end-pit lake model behaviour. SOD is a dominant contributor to oxygen depletion in wetlands. The function and sustainability of a wetland ecosystem depends on the biochemical processes occurring at the sediment-water interface. The biochemical reactions associated with natural sediment can change with the addition of oil sands processed material (OSPM), which can affect SOD and ecosystem viability. It is important to establishing the biotic and abiotic controls of SOD. In order to evaluate the effectiveness of current wetland reclamation designs, it is important to establish the biotic and abiotic controls of SOD. The REDOX chemistry of fresh tailings sediment (MFT) was measured in this laboratory microcosm to determine the chemical and biological influences, and to study the role of developing microbial communities as new mature fine tailings (MFT) age. The study evaluated the changes in the main chemical, physical and biological populations of the MFT in both aerobic and anaerobic microcosms. A combination of microelectrode arrays and DNA profiling at the tailings water interface was used in the study.

  15. Fine root dynamics in lodgepole pine and white spruce stands along productivity gradients in reclaimed oil sands sites.

    Science.gov (United States)

    Jamro, Ghulam Murtaza; Chang, Scott X; Naeth, M Anne; Duan, Min; House, Jason

    2015-10-01

    Open-pit mining activities in the oil sands region of Alberta, Canada, create disturbed lands that, by law, must be reclaimed to a land capability equivalent to that existed before the disturbance. Re-establishment of forest cover will be affected by the production and turnover rate of fine roots. However, the relationship between fine root dynamics and tree growth has not been studied in reclaimed oil sands sites. Fine root properties (root length density, mean surface area, total root biomass, and rates of root production, turnover, and decomposition) were assessed from May to October 2011 and 2012 using sequential coring and ingrowth core methods in lodgepole pine (Pinus contorta Dougl.) and white spruce (Picea glauca (Moench.) Voss) stands. The pine and spruce stands were planted on peat mineral soil mix placed over tailings sand and overburden substrates, respectively, in reclaimed oil sands sites in Alberta. We selected stands that form a productivity gradient (low, medium, and high productivities) of each tree species based on differences in tree height and diameter at breast height (DBH) increments. In lodgepole pine stands, fine root length density and fine root production, and turnover rates were in the order of high > medium > low productivity sites and were positively correlated with tree height and DBH and negatively correlated with soil salinity (P < 0.05). In white spruce stands, fine root surface area was the only parameter that increased along the productivity gradient and was negatively correlated with soil compaction. In conclusion, fine root dynamics along the stand productivity gradients were closely linked to stand productivity and were affected by limiting soil properties related to the specific substrate used for reconstructing the reclaimed soil. Understanding the impact of soil properties on fine root dynamics and overall stand productivity will help improve land reclamation outcomes.

  16. Initial geochemical characteristics of fluid fine tailings in an oil sands end pit lake

    Energy Technology Data Exchange (ETDEWEB)

    Dompierre, Kathryn A. [Department of Civil and Geological Engineering, University of Saskatchewan, Saskatoon, Saskatchewan, Canada S7N 5A9 (Canada); Lindsay, Matthew B.J., E-mail: matt.lindsay@usask.ca [Department of Geological Sciences, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E2 (Canada); Cruz-Hernández, Pablo [Department of Geology, University of Huelva, Campus ‘El Carmen’, E-21071 Huelva (Spain); Halferdahl, Geoffrey M. [Environmental Research and Development, Syncrude Canada Limited, Edmonton, Alberta T6N 1H4 (Canada)

    2016-06-15

    Geochemical characteristics of fluid fine tailings (FFT) were examined in Base Mine Lake (BML), which is the first full-scale demonstration oil sands end pit lake (EPL) in northern Alberta, Canada. Approximately 186 Mm{sup 3} of FFT was deposited between 1994 and 2012, before BML was established on December 31, 2012. Bulk FFT samples (n = 588) were collected in July and August 2013 at various depths at 15 sampling sites. Temperature, solid content, electrical conductivity (EC), pH, Eh and alkalinity were measured for all samples. Detailed geochemical analyses were performed on a subset of samples (n = 284). Pore-water pH decreased with depth by approximately 0.5 within the upper 10 m of the FFT. Major pore-water constituents included Na (880 ± 96 mg L{sup −1}) and Cl (560 ± 95 mg L{sup −1}); Ca (19 ± 4.1 mg L{sup −1}), Mg (11 ± 2.0 mg L{sup −1}), K (16 ± 2.3 mg L{sup −1}) and NH{sub 3} (9.9 ± 4.7 mg L{sup −1}) were consistently observed. Iron and Mn concentrations were low within FFT pore water, whereas SO{sub 4} concentrations decreased sharply across the FFT–water interface. Geochemical modeling indicated that FeS{sub (s)} precipitation was favoured under SO{sub 4}-reducing conditions. Pore water was also under-saturated with respect to gypsum [CaSO{sub 4}·2H{sub 2}O], and near saturation with respect to calcite [CaCO{sub 3}], dolomite [CaMg(CO{sub 3}){sub 2}] and siderite [FeCO{sub 3}]. X-ray diffraction (XRD) suggested that carbonate-mineral dissolution largely depleted calcite and dolomite. X-ray absorption near edge structure (XANES) spectroscopy revealed the presence of FeS{sub (s)}, pyrite [FeS{sub 2}], and siderite. Carbonate-mineral dissolution and secondary mineral precipitation have likely contributed to FFT dewatering and settlement. However, the long-term importance of these processes within EPLs remains unknown. These results provide a reference for assessing the long-term geochemical evolution of oil sands EPLs, and offer

  17. Control of phlebotomine sand flies with vertical fine-mesh nets.

    Science.gov (United States)

    Faiman, R; Cuño, R; Warburg, A

    2009-07-01

    Insecticide-treated vertical net barriers were used to intercept foraging sand flies. Two different nets were draped on fenced enclosures (10 by 10 m; 2 m high) in the central Jordan Valley. One enclosure was draped with a deltamethrin-impregnated net (PermaNet, 225 holes/in2). The holes of this net are sufficiently large to allow sand flies to pass through but not without coming in close contact with the mesh. The other enclosure was covered with SpiderNet+ (1,240 holes/in2) and sprayed with beta-cyfluthrin. Sand flies were captured inside and outside the enclosures before and after draping with the nets using CO2-baited CDC traps or CDC light traps. Both barrier types exhibited > 90% efficacy in blocking sand flies from entering the enclosures (P sand flies approaching houses from their natural habitats. Sand flies were monitored on all sides of the barrier using CO2-baited CDC traps or CDC light traps. Results showed a 60% reduction in the mean number of sand flies trapped behind the net compared with the untreated areas adjacent to it (P sand flies arriving at inhabited areas.

  18. Numerical simulation of fine oil sand tailings drying in test cells

    NARCIS (Netherlands)

    Vardon, P.J.; Nijssen, T.; Yao, Y.; Van Tol, A.F.

    2014-01-01

    As a promising technology in disposal of mature fine tailings (MFT), atmospheric fines drying (AFD) is currently being implemented on a commercial scale at Shell Canada’s Muskeg River Mine near Fort McMurray, Alberta. AFD involves the use of a polymer flocculent to bind fine particles in MFT

  19. Imidacloprid transport and sorption nonequilibrium in single and multilayered columns of Immokalee fine sand.

    Science.gov (United States)

    Leiva, Jorge A; Nkedi-Kizza, Peter; Morgan, Kelly T; Kadyampakeni, Davie M

    2017-01-01

    Imidacloprid (IMD) is a neonicotinoid pesticide soil-drenched to many crops to control piercing-sucking insects such as the Asian citrus psyllid (ACP). Neonicotinoids are persistent in the environment and transport analyses are helpful estimate leaching potential from soils that could result in groundwater pollution. The objective of this study was to analyze IMD breakthrough under saturated water flow in soil columns packed with three horizons (A, E, Bh) of Immokalee Fine Sand (IFS). Also, we used the dimensionless form of the convective-dispersive model (CD-Model) to compare the optimized transport parameters from each column experiment (retardation factor, R; fraction of instantaneous-to-total retardation, β; and mass transfer coefficient, ω) with the parameters obtained from sorption batch equilibria and sorption kinetics. The tracer (Cl-) breakthrough curves (BTCs) were symmetrical and properly described by the CD-Model. IMD BTCs from A, Bh, and multilayered [A+E+Bh] soil columns showed steep fronts and tailing that were well described by the one-site nonequilibrium (OSNE) model, which was an evidence of non-ideal transport due to IMD mass transfer into the soil organic matter. In general, IMD was weakly-sorbed in the A and Bh horizons (R values of 3.72 ± 0.04 and 3.08 ± 0.07, respectively), and almost no retardation was observed in the E horizon (R = 1.20 ± 0.02) due to its low organic matter content (0.3%). Using the HYDRUS-1D package, optimized parameters (R, β, ω) from the individual columns successfully simulated IMD transport in a multilayered column mimicking an IFS soil profile. These column studies and corresponding simulations agreed with previous findings from batch sorption equilibria and kinetics experiments, where IMD showed one-site kinetic mass transfer between soil surfaces and soil solution. Ideally, sandy soils should be maintained unsaturated by crop irrigation systems and rainfall monitoring during and after soil-drench application

  20. Induction of chromosome aberrations in cultured human lymphocytes treated with sand dust storm fine particles (PM2.5).

    Science.gov (United States)

    Wei, Aili; Meng, Ziqiang

    2006-09-30

    The clastogenic activity of airborne air fine particulate matter (PM2.5, particulates with an aerodynamic diameter dust storm PM2.5 and its extract. In order to investigate the clastogenic activity of sand dust storm PM2.5 (include its organic and inorganic extract) on human lymphocytes, the normal PM2.5 and sand dust storm PM2.5 samples were collected in Wuwei city (Gansu Province) and Baotou city (Inner Mongolia), China. The chromosomal aberration (CA) test was employed and the cells were treated with 0, 33, 100, 300 microg ml(-1) sand dust storm or normal ambient air PM2.5 suspension (physiological saline as solvent control), or inorganic extract (0, 75, 150, 300 microg ml(-1), physiological saline as solvent control) or organic extract (0, 20, 40, 80 microg ml(-1), DMSO as solvent control) at the beginning of the cell culture. The results indicated that sand dust storm PM2.5 and its extract as well as normal samples can induce increase in CA frequency. With the increase of treatment concentrations the CA frequency increased and the mitotic index (MI) values declined in a dose-response manner. In the same concentrates, the CA frequency of normal ambient air PM2.5 and its extract were significant higher than those of sand dust storm PM2.5 (P0.05). The toxicity of sand dust storm PM2.5 and its extract at high dose is very potent. CA frequency of normal PM2.5 (include its organic extract) from Baotou were higher than those of Wuwei especially in low and middle dose (Pdust storm PM2.5 (include its all extract) was not significant different between the cities (P>0.05).

  1. Evaluation of micronucleus induction of sand dust storm fine particles (PM(2.5)) in human blood lymphocytes.

    Science.gov (United States)

    Wei, Aili; Meng, Ziqiang

    2006-11-01

    Sand dust storms are common phenomena in the arid and semi-arid regions. Previous studies have demonstrated that the airborne air fine particulate matter (PM(2.5), particulates with an aerodynamic diameter ≤2.5μm) and its extracts can induce human genetic damage of lymphocytes such as micronucleus formation, chromosomal aberration and so on. However, little is known about the health risks associated with sand dust storm PM(2.5) and its extracts. The aim of the present study is to investigate the micronucleus induction of sand dust storm PM(2.5) (include its organic and inorganic extract) from two different towns on human lymphocytes. The samples of normal PM(2.5) and sand dust storm PM(2.5) were collected in Wuwei (Gansu Province) and Baotou (Inner Mongolia), China. The cytochalasin-B cytokinesis-block test was employed and the cells were treated with 0, 33, 100, 300μgml(-1) sand dust storm PM(2.5) or normal ambient air PM(2.5) suspension (physiological saline as solvent control), or inorganic extract (0, 75, 150, 300μgml(-1), physiological saline as solvent control) or organic extract (0, 20, 40, 80μgml(-1), DMSO as solvent control) at the beginning of the cell culture. Both sand dust storm and normal PM(2.5) and their extract treatment cultures revealed an increase in the frequency of micronucleus. With the increase of treatment concentrations the frequency of micronucleus increased and the nuclear division index (NDI) values declined in a dose-response manner (Pdust storm PM(2.5) (P0.05). The toxicity of sand dust storm PM(2.5) and its extract at high dose is very potent. The frequency of micronucleus of normal PM(2.5) (include its organic extract) from Baotou were higher than those of Wuwei especially in low and middle dose (Pdust storm PM(2.5) (include its all extract) was not significantly different between the towns (P>0.05).

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

    DEFF Research Database (Denmark)

    Kessler, Timo Christian; Comunian, Alessandro; Oriani, Fabio

    2013-01-01

    . However, two-dimensional training images acquired by outcrop mapping are of limited use to generate three-dimensional realizations with MPS. One can use a technique that consists in splitting the 3D domain into a set of slices in various directions that are sequentially simulated and reassembled into a 3D...... on till outcrops producing binary images of geological cross-sections capturing the size, shape and distribution of individual features. Sand lenses occur as elongated, anisotropic geobodies that vary in size and extent. Besides, sand lenses show strong non-stationary patterns on section images...

  3. Sand Cement Brick Containing Recycled Concrete Aggregate as Fine-Aggregate Replacement

    Directory of Open Access Journals (Sweden)

    Sheikh Khalid Faisal

    2017-01-01

    Full Text Available Nowadays, the usage amount of the concrete is increasing drastically. The construction industry is a huge consumer of natural consumer. It is also producing the huge wastage products. The usage of concrete has been charged to be not environmentally friendly due to depletion of reserve natural resources, high energy consumption and disposal issues. The conservation of natural resources and reduction of disposal site by reuse and recycling waste material was interest possibilites. The aim of this study is to determine the physical and mechanical properties of sand cement brick containing recycled concrete aggregate and to determine the optimum mix ratio containing recycled concrete aggregate. An experiment done by comparing the result of control specimen using 100% natural sand with recycled concrete aggregate replacement specimen by weight for 55%, 65%, and 75%. The sample was tested under density, compressive strength, flexural strength and water absorption to study the effect of using recycled concrete aggregate on the physical and mechanical properties of bricks. The result shows that the replacement of natural sand by recycled concrete aggregate at the level of 55% provide the highest compressive and flexural strength compared to other percentage and control specimen. However, if the replacement higher than 55%, the strength of brick was decreased for compressive and flexural strength, respectively. The relationship of compressive-flexural strength is determined from statistical analysis and the predicted result can be obtained by using equation ff,RCA = 0.5375 (fc0.3272.

  4. Mechanical and Durability Properties of Concrete Made with Used Foundry Sand as Fine Aggregate

    Directory of Open Access Journals (Sweden)

    G. Ganesh Prabhu

    2015-01-01

    Full Text Available In recent years, the construction industry has been faced with a decline in the availability of natural sand due to the growth of the industry. On the other hand, the metal casting industries are being forced to find ways to safely dispose of waste foundry sand (FS. With the aim of resolving both of these issues, an investigation was carried out on the reuse of waste FS as an alternative material to natural sand in concrete production, satisfied with relevant international standards. The physical and chemical properties of the FS were addressed. The influence of FS on the behaviour of concrete was evaluated through strength and durability properties. The test results revealed that compared to the concrete mixtures with a substitution rate of 30%, the control mixture had a strength value that was only 6.3% higher, and this enhancement is not particularly high. In a similar manner, the durability properties of the concrete mixtures containing FS up to 30% were relatively close to those of control mixture. From the test results, it is suggested that FS with a substitution rate of up to 30% can be effectively used in concrete production without affecting the strength and durability properties of the concrete.

  5. Recycling of End of Life Concrete Fines into Hardened Cement and Clean Sand

    NARCIS (Netherlands)

    Lotfi, S.; Rem, P.C.

    2016-01-01

    One of the massive by-products of concrete to concrete recycling is the crushed concrete fines, that is often 0 - 4mm. Although the construction sector is to some extent familiar with the utilization of the recycled coarse fraction (>4 mm), at present there is no high-quality application for

  6. Chemical mass transport between fluid fine tailings and the overlying water cover of an oil sands end pit lake

    Science.gov (United States)

    Dompierre, Kathryn A.; Barbour, S. Lee; North, Rebecca L.; Carey, Sean K.; Lindsay, Matthew B. J.

    2017-06-01

    Fluid fine tailings (FFT) are a principal by-product of the bitumen extraction process at oil sands mines. Base Mine Lake (BML)—the first full-scale demonstration oil sands end pit lake (EPL)—contains approximately 1.9 × 108 m3 of FFT stored under a water cover within a decommissioned mine pit. Chemical mass transfer from the FFT to the water cover can occur via two key processes: (1) advection-dispersion driven by tailings settlement; and (2) FFT disturbance due to fluid movement in the water cover. Dissolved chloride (Cl) was used to evaluate the water cover mass balance and to track mass transport within the underlying FFT based on field sampling and numerical modeling. Results indicated that FFT was the dominant Cl source to the water cover and that the FFT is exhibiting a transient advection-dispersion mass transport regime with intermittent disturbance near the FFT-water interface. The advective pore water flux was estimated by the mass balance to be 0.002 m3 m-2 d-1, which represents 0.73 m of FFT settlement per year. However, the FFT pore water Cl concentrations and corresponding mass transport simulations indicated that advection rates and disturbance depths vary between sample locations. The disturbance depth was estimated to vary with location between 0.75 and 0.95 m. This investigation provides valuable insight for assessing the geochemical evolution of the water cover and performance of EPLs as an oil sands reclamation strategy.

  7. Bio-physicochemical effects of gamma irradiation treatment for naphthenic acids in oil sands fluid fine tailings

    Energy Technology Data Exchange (ETDEWEB)

    Boudens, Ryan; Reid, Thomas; VanMensel, Danielle; Sabari Prakasanm, M.R. [Great Lakes Institute for Environmental Research, University of Windsor, Windsor, ON (Canada); Ciborowski, Jan J.H. [Biological Sciences, University of Windsor, Windsor, ON (Canada); Weisener, Christopher G., E-mail: weisener@uwindsor.ca [Great Lakes Institute for Environmental Research, University of Windsor, Windsor, ON (Canada)

    2016-01-01

    Naphthenic acids (NAs) are persistent compounds that are components of most petroleum, including those found in the Athabasca oil sands. Their presence in freshly processed tailings is of significant environmental concern due to their toxicity to aquatic organisms. Gamma irradiation (GI) was used to reduce the toxicity and concentration of NAs in oil sands process water (OSPW) and fluid fine tailings (FFT). This investigation systematically studied the impact of GI on the biogeochemical development and progressive reduction of toxicity using laboratory incubations of fresh and aged tailings under anoxic and oxic conditions. GI reduced NA concentrations in OSPW by up to 97% in OSPW and in FFT by 85%. The GI-treated FFT exhibited increased rates of biogeochemical change, dependent on the age of the tailings source. Dissolved oxygen (DO) flux was enhanced in GI-treated FFT from fresh and aged source materials, whereas hydrogen sulfide (HS{sup −}) flux was stimulated only in the fresh FFT. Acute toxicity to Vibrio fischeri was immediately reduced following GI treatment of fresh OSPW. GI treatment followed by 4-week incubation reduced toxicity of aged OSPW to V. fischeri. - Highlights: • Gamma irradiation substantially reduced concentrations of ecotoxic naphthenic acids • Acute toxicity was reduced in gamma irradiated process water • Gamma irradiated tailings exhibited increased rates of microbial respiration.

  8. Silica nanoparticles for fines stabilization in Ottawa sand packed beds; Uso de nanopartículas de sílice para la estabilización de finos en lechos empacados de arena Ottawa

    Directory of Open Access Journals (Sweden)

    Farid Bernardo Cortes

    Full Text Available To determine the problem of fines migration on packed beds and offer a possible solution for this issue, an adsorptive system of packed beds was developed for experimental simulation of fines migration and stabilization by using silica nanoparticles. The adsorbent beds were prepared with Ottawa sand and glass spheres (average radius of 0.53 mm. Three different sand beds were used in the investigation: clean sand (water- wet system, sand submitted to a damage process using an extra-heavy Colombian crude oil (oil-wet system and sand treated with silica nanoparticles (5-15 nm. Fines suspension was prepared with alumina nanoparticles (50 nm and distilled water. Results show that beds treated with silica nanoparticles present idealized patterns for the rupture curve, indicating that silica nanoparticles capture and retain fines, decreasing fines migration due to their adsorption capacity.

  9. Benthic fluxes of oxygen and nutrients in sublittoral fine sands in a north-western Mediterranean coastal area

    Science.gov (United States)

    Sospedra, J.; Falco, S.; Morata, T.; Gadea, I.; Rodilla, M.

    2015-04-01

    Traditionally, benthic metabolism in sublittoral permeable sands have not been widely studied, although these sands can have a direct and transcendental impact in coastal ecosystems. This study aims to determine oxygen and nutrient fluxes at the sediment-water interface and the study of possible interactions among environmental variables and the benthic metabolism in well-sorted fine sands. Eight sampling campaigns were carried out over the annual cycle in the eastern coast of Spain (NW Mediterranean) at 9 m depth station with permeable bottoms. Water column and sediment samples were collected in order to determine physico-chemical and biological variables. Moreover, in situ incubations were performed to estimate the exchange of dissolved solutes in the sediment-water interface using dark and light benthic chambers. Biochemical compounds at the sediment surface ranged between 160 and 744 μg g-1 for proteins, 296 and 702 μg g-1 for carbohydrates, and between 327 and 1224 μg C g-1 for biopolymeric carbon. Chloroplastic pigment equivalents in sediments were mainly composed by chlorophyll a (1.81-2.89 μg g-1). These sedimentary organic descriptors indicated oligotrophic conditions according to the biochemical approach used. In this sense, the most abundant species in the macrobenthic community were sensitive to organic enrichment. In dark conditions, benthic fluxes behaved as a sink of oxygen and a source of nutrients. Oxygen fluxes (between -26,610 and -10,635 μmol m-2 d-1) were related with labile organic fraction (r=-0.86, p<0.01 with biopolymeric carbon; r=-0.91, p<0.01 with chloroplastic pigment equivalents). Daily fluxes of dissolved oxygen, that were obtained by adding light and dark fluxes, were only positive in spring campaigns (6966 μmol m-2 d-1) owing to the highest incident irradiance levels (r=0.98, p<0.01) that stimulate microphytobenthic primary production. Microphytobenthos played an important role on benthic metabolism and was the main primary

  10. Nd-Sr isotope geochemistry of fine-grained sands in the basin-type deserts, West China: Implications for the source mechanism and atmospheric transport

    Science.gov (United States)

    Rao, Wenbo; Tan, Hongbing; Chen, Jun; Ji, Junfeng; Chen, Yang; Pan, Yaodong; Zhang, Wenbing

    2015-10-01

    The basin-type deserts of West China are among the greatest dust emission areas in the world. Mineral dust that is emitted from the deserts is transported and deposited in east-central China and even in far-east regions. This study investigates the Nd-Sr isotopic compositions of fine-grained surface sands (China (the Taklimakan and Gurbantunggut deserts) to clarify the source areas and atmospheric transport of mineral dust. The Nd isotopes are useful for tracing the provenance and transport of sediments because they depend on the source rocks and are usually used with Sr isotopes which are affected by multiple factors such as chemical weathering, particle sorting and parent rock. The radiogenic isotopic compositions of the dune sands from the Taklimakan Desert range from εNd (0) = - 10.9 to - 15 and 87Sr/86Sr = 0.714 to 0.718, while those of the dune sands from the Gurbantunggut Desert range from εNd (0) = - 4.5 to - 6 and 87Sr/86Sr = 0.711 to 0.713. The isotopic compositions of the fine-grained surface sands are not spatially uniform within each desert and are controlled by the lithological characteristics of the tectonic units in which the deserts are located. The isotopic comparison of the dune sands with other sediments indicates that tectonic denudation and fluvial processes are the main mechanisms of fine particle production of the modern desert sands. In terms of isotope analyses and forward trajectory results, it is further found that the mineral dust is deposited not only in proximal areas, such as the Hexi Corridor, the Chinese Loess Plateau and the Tibet-Qinghai Plateau, but also in distal regions, such as Japan, the Pacific Ocean and Greenland once it is blown out of the Taklimakan Desert. However, the transport and sinks of mineral dust vary with the atmospheric currents.

  11. The fine sand Abra alba community of the Bay of Morlaix twenty years after the Amoco Cadiz oil spill

    Energy Technology Data Exchange (ETDEWEB)

    Dauvin, J.-C. [CNRS-UPRES-A Elico, Wimereux (France). Station Marine de Wimereux

    1998-09-01

    The fine sand Abra alba community from the Bay of Morlaix (western English Channel) was strongly affected by the Amoco Cadiz oil spill of April 1978. The long term changes in the community (1977-1996) show that reconstitution of this community is slow (over 10 yr). A progressive recolonization by amphipod Ampelisca populations constituting the dominant species is observed. The results show that it is necessary to survey the affected communities for a long period of time (> 10 yr) after an event to identify the real ecological impact of an oil spill. The abiotic and biotic factor existing in the Bay of Morlaix are favorable to the establishment and the persistence of stable dominant Ampelisca populations in time. The `climax` concept seems to be applicable to this type of stable environment. The soft-bottom Abra alba community of the Bay of Morlaix may only support a maximal carrying capacity of approximately 10-11 g m{sup -2} (mean annual biomass in decalcified dry weight). The deficit of production during 11 annual cycles may have affected the fish biomass feeding on this community. (author)

  12. The fine sand Abra alba community of the Bay of Morlaix twenty years after the Amoco Cadiz oil spill

    Energy Technology Data Exchange (ETDEWEB)

    Dauvin, J.-C. [CNRS-UPRES-A Elico, Wimereux (France). Station Marine de Wimereux

    1998-09-01

    The fine sand Abra alba community from the Bay of Morlaix (western English Channel) was strongly affected by the Amoco Cadiz oil spill of April 1978. The long term changes in the community (1977-1996) show that reconstitution of this community is slow (over 10 yr). A progressive recolonization by amphipod Ampelisca populations constituting the dominant species is observed. The results show that it is necessary to survey the affected communities for a long period of time (> 10 yr) after an event to identify the real ecological impact of an oil spill. The abiotic and biotic factor existing in the Bay of Morlaix are favorable to the establishment and the persistence of stable dominant Ampelisca populations in time. The 'climax' concept seems to be applicable to this type of stable environment. The soft-bottom Abra alba community of the Bay of Morlaix may only support a maximal carrying capacity ofapproximately 10-11 g m{sup -2} (mean annual biomass in decalcified dry weight). The deficit of production during 11 annual cycles may have affected the fish biomass feeding on this community. (author)

  13. The well sorted fine sand community from the western Mediterranean Sea: A resistant and resilient marine habitat under diverse human pressures.

    Science.gov (United States)

    Dauvin, Jean-Claude; Bakalem, Ali; Baffreau, Alexandrine; Delecrin, Claire; Bellan, Gérard; Lardicci, Claudio; Balestri, Elena; Sardá, Rafael; Grimes, Samir

    2017-05-01

    The Biocoenosis of Well Sorted Fine Sands (WSFS) (SFBC, Sables Fins Bien Calibrés in French) is a Mediterranean community very well delimited by bathymetry (2-25 m) and sedimentology (>90% of fine sand) occurring in zones with relatively strong hydrodynamics. In this study focused on sites located along the Algerian, French, Italian and Spanish coasts of the Western Basin of the Mediterranean Sea (WBMS) we aim to compare the structure, ecological status and diversity of the macrofauna of the WSFS and examine the effects of recent human pressures on the state of this shallow macrobenthic community. We assess the ecological status and functioning of these WSFS using three categories of benthic indices: a) five indices based on classification of species into ecological groups, AMBI, BO2A, BPOFA, IQ and IP, b) the ITI index based on classification of species in trophic groups, and c) the Shannon H' index, and the Biological Traits Analysis (BTA), which is an alternative method to relative taxon composition analysis and integrative indices. Cluster analyses show that each zone show a particular taxonomic richness and dominant species. The seven benthic indices reveal that the macrobenthos of the WSFS of the four coastal zones show good or high Quality Status, except for one location on the Algerian coast (the Djendjen site) in 1997. BTA highlights the presence of three groups of species: 1) typical characteristic species; 2) indicator species of enrichment of fine particles and organic matter, and 3) coarse sand species which are accessorily found on fine sand. Finally, the WSFS which are naturally subject to regular natural physical perturbations show a high resilience after human pressures but are very sensitive to changes in the input of organic matter. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Brillouin, Prof. Leon

    Indian Academy of Sciences (India)

    Home; Fellowship. Fellow Profile. Elected: 1939 Honorary. Brillouin, Prof. Leon. Date of birth: 7 August 1889. Date of death: 4 October 1969 ... Posted on 21 December 2017. ASTROPHYSICS: An Observational View of the Universe. Math Art and Design: MAD about Math, Math Education and Outreach. Math and Finance ...

  15. Sand resistance of sunscreens.

    Science.gov (United States)

    Caswell, Michael; Wood, Caryl; Martinez, Alexa

    2012-01-01

    Like water resistance in sunscreens, sand resistance in sunscreens is the ability of the sunscreen to retain its effectiveness while undergoing sand treatment. The influence of the type of sand on the sand resistance of sunscreens has not been described. The sand resistance of a control standard sunscreen, P2, and data on three grades of Quickrete commercial grade sand, #1961, #1962, and #1152, are described. These sands represent a fine sand, a medium sand, and an all-purpose sand. Using the methodology described in the 2007 proposed amendment of the Final Monograph (1) with one exception, we obtained an SPF of 16.5 (1.6) for the control standard, compared to the expected SPF of 16.3 (3.4). After a five-minute treatment of sand #1961, #1962, or #1151, the SPF of the control standard was 18.3 (1.6), 18.4 (2.0), and 17.5 (2.2), respectively. Thus, all three sands exhibited a similar sand-resistance response. Thus, there was no significant difference in the average SPF with and without sand. The medium grade sand, Quickrete commercial grade #1962, was preferred for sand-resistance testing because the fine sand was difficult to remove from the subject's backs and the coarse sand was unpleasant to the subjects.

  16. Consolidation and atmospheric drying of fine oil sand tailings : Comparison of blind simulations and field scale results

    NARCIS (Netherlands)

    Vardon, P.J.; Yao, Y.; van Paassen, L.A.; van Tol, A.F.; Sego, D.C.; Wilson, G.W.; Beier, N.A.

    2016-01-01

    This paper presents a comparison between blind predictions of field tests of atmospheric drying of mature fine tailings (MFT) presented in IOSTC 2014 and field results. The numerical simulation of the consolidation and atmospheric drying of selfweight consolidating fine material is challenging and

  17. Impact of the Aegean Sea oil spill on the subtidal fine sand macrobenthic community of the Ares-Betanzos Ria (Northwest Spain)

    Energy Technology Data Exchange (ETDEWEB)

    Gomez Gesteira, J.L. [Vigo Univ. (Spain). Grupo de Fisica Oceanographic y de Costas; Dauvin, J.C. [Universite des Sciences et Technologies de Lille, Wimereux (France). Station Marine

    2005-09-01

    Two sites located in the sublittoral fine-sand macrobenthic community of the Ares-Betanzos Ria were sampled over four years (December 1992-November 1996) in the wake of the Aegean Sea oil spill. This sampling revealed that the petroleum had affected the structure and abundance of this community, as well as the number of taxa present. In this context, the results of the biotic index and the biotic coefficient were insufficient; however, study of the synthetic parameters, particularly through multivariate analysis, showed that the community went through three successive and distinct phases over time. A short period of high mortality in some species, especially amphipods, was followed by a period of low abundance that lasted until the spring of 1995. A period of recovery began in the second half of 1995 and continued through to the end of 1996, when the survey ended. The community showed a gradual evolution back towards the conditions observed immediately after the spill, when abundance of the more resistant species was still high. Despite this similarity, the last period exhibits a new structure, clearly separate from the two previous periods. This study provides information about the short-term effects of the Aegean Sea oil spill on the fine sand bottoms of the sites surveyed in the Ares-Betanzos Ria. This information could also serve as a baseline for identifying the effects of a more recent accident, the Prestige oil spill, in which similar communities in other Galician rias were polluted in 2002-2003. (author)

  18. Fine-Scale Volume Heterogeneity in a Mixed Sand/Mud Sediment Off Fort Walton Beach, FL

    Science.gov (United States)

    2010-07-01

    lenses within the mud drape. Lens- shaped mud inclusions within the sand sediment, or (lasers, were cre- ated when the mud that settled into the troughs...tected from resuspension by bottom currents. Over the course of the experiment, subsequent storm events broke up the surface mud layer into small clasts ...grained fractions (silt and clay sizes) were rele- gated to discrete layers, lenses, or clasts , occurring in 45% of all collected cores but occupying only

  19. Analysis of fine-dispersed chalk usage as mineral additive in the composition of sand aggrerate concrete

    Directory of Open Access Journals (Sweden)

    Светлана Николаевна Чепурная

    2016-12-01

    Full Text Available The research results of fine-disperse chalk addition on physical and mechanical properties of the cement stone and concrete are shown. It is determined that fine-disperse chalk addition in the binder composition increases the content of ultrafine particles. The chalk particles fill the pore space between the cement particles, increasing the packing density, which leads to a density increase, which consequently leads to improved physical and mechanical properties of the concrete: water tightness, cold resistance, corrosion resistance, crack resistance and other properties

  20. Fine-scale patterns of vegetation assembly in the monitoring of changes in coastal sand-dune landscapes

    Directory of Open Access Journals (Sweden)

    J. Honrado

    2010-02-01

    Full Text Available Understanding dune ecosystem responses to multi-scale environmental changes can provide the framework for reliable forecasts and cost-efficient protocols for detecting shifts in prevailing coastal dynamics. Based on the hypothesis that stress and disturbance interact as primary community controls in coastal dunes, we studied the fine-scale floristic assembly of foredune vegetation, in its relation to topography, along regional and local environmental gradients in the 200 km long coastline of northern Portugal, encompassing a major biogeographic transition in western Europe. Thirty topographic profiles perpendicular to the shoreline were recorded at ten sites along the regional climate gradient, and vegetation was sampled by recording the frequency of plant species along those profiles. Quantitative topographic attributes of vegetated dune profiles (e.g. length or height exhibited wide variations relatable to differences in prevailing coastal dynamics. Metrics of taxonomic diversity (e.g. total species richness and its additive beta component and of the functional composition of vegetation were highly correlated to attributes of dune topography. Under transgressive dynamics, vegetation profiles have fewer species, increased dominance, lower turnover rates, and lower total vegetation cover. These changes may drive a decrease in structural and functional diversity, with important consequences for resistance, resilience and other ecosystem properties. Moreover, differences in both vegetation assembly (in meta-stable dunes and response to increased disturbance (in eroding dunes between distinct biogeographic contexts highlight a possible decline in facilitation efficiency under extreme physical stress (i.e. under Mediterranean climate and support the significance of functional approaches in the study of local ecosystem responses to disturbance along regional gradients. Our results strongly suggest that assessing fine-scale community assembly can

  1. Female genital mutilation in Sierra Leone

    African Journals Online (AJOL)

    AJRH Managing Editor

    Health, College of Medicine and Allied Health Sciences, University of Sierra Leone; 3Plan Sierra Leone, Freetown, Sierra Leone ... Abstract. The objectives of this study were to identify decision makers for FGM and determine whether medicalization takes place in ...... cutting: research findings, gaps and directions. Culture ...

  2. African Journals Online: Sierra Leone

    African Journals Online (AJOL)

    The Sierra Leone Journal of Biomedical Research publishes papers in all fields of Medicine and Allied Health Sciences including Basic Medical Sciences, Clinical Sciences, Dental Sciences, Behavioural Sciences, Biomedical Engineering, Molecular Biology, Pharmaceutical Sciences, Biotechnology in relation to Medicine, ...

  3. Reading Comprehension Instruction Practices in Sierra Leone

    NARCIS (Netherlands)

    Hersbach, S.; Denessen, E.J.P.G.; Droop, W.

    2014-01-01

    Aim: In this study an attempt was made to give insight in the way reading comprehension is taught in Sierra Leone. Attention was paid to the didactical strategies and the materials used during reading comprehension instruction. Methodology: Primary school teachers in Sierra Leone (N=43) were

  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. Measurement of fine particulate matter water-soluble inorganic species and precursor gases in the Alberta Oil Sands Region using an improved semicontinuous monitor.

    Science.gov (United States)

    Hsu, Yu-Mei; Clair, Thomas A

    2015-04-01

    The ambient ion monitor-ion chromatography (AIM-IC) system, which provides hourly measurements of the main chemical components of PM2.5 (particulate matter with an aerodynamic diametergases, was evaluated and deployed from May to July 2011 and April to December 2013 in the Athabasca Oil Sands Region (AOSR) of northeastern Alberta, Canada. The collection efficiencies for the gas-phase SO2 and HNO3 using the cellulose membrane were 96% and 100%, respectively, and the collection efficiency of NH3 using the nylon membrane was 100%. The AIM-IC was compared with a collocated annular denuder sampling system (ADSS) and a Federal Reference Method (FRM) Partisol PM2.5 sampler. The correlation coefficients of SO4(2-) concentrations between the AIM-IC and ADSS and between the AIM-IC and the Partisol PM2.5 sampler were 0.98 and 0.95, respectively. The comparisons also showed no statistically significant difference between the measurement sets, suggesting that the AIM-IC measurements of the PM2.5 chemical composition are comparable to the ADSS and Partisol PM2.5 methods. NH3 concentration in the summer (mean±standard deviation, 1.9±0.7 µg m(-3)) was higher than in the winter (1.3±0.9 µg m(-3)). HNO3 and NO3- concentrations were generally low in the AOSR, and especially in the winter months. NH4+ (0.94±0.96 µg m(-3)) and SO4(2-) (0.58±0.93 µg m(-3)) were the major ionic species of PM2.5. Direct SO2 emissions from oil sands processing operations influenced ambient particulate NH4+ and SO4(2-) values, with hourly concentrations of NH4+ and SO4(2-) measured downwind (~30 km away from the stack) at 10 and 28 µg m(-3). During the regional forest fire event in 2011, high concentrations of NO3-, NH4+, HNO3, NH3, and PM2.5 were observed and the corresponding maximum hourly concentrations were 31, 15, 9.6, 89, and >450 (the upper limit of PM2.5 measurement) µg m(-3), suggesting the formation of NH4NO3. The AOSR in Canada is one of the most scrutinized industrial regions in the

  6. The Special Court for Sierra Leone

    DEFF Research Database (Denmark)

    Damgaard, Ciara Therése

    2004-01-01

    The focus of this article is the Special Court for Sierra Leone and the extent to which it can be said that the Special Court has already challenged, or will, in the future, challenge the tradition of impunity for gender-based crimes. In this regard, an analysis is undertaken of the Special Court......'s Statute, Rules of Procedure and Evidence and practice to date, in order to determine its treatment of gender-based crimes and whether it can be said that the Special Court for Sierra Leone challenges the tradition of impunity for gender-based crimes. Udgivelsesdato: december 2004...

  7. The Special Court for Sierra Leone

    DEFF Research Database (Denmark)

    Damgaard, Ciara Therése

    2004-01-01

    's Statute, Rules of Procedure and Evidence and practice to date, in order to determine its treatment of gender-based crimes and whether it can be said that the Special Court for Sierra Leone challenges the tradition of impunity for gender-based crimes. Udgivelsesdato: december 2004......The focus of this article is the Special Court for Sierra Leone and the extent to which it can be said that the Special Court has already challenged, or will, in the future, challenge the tradition of impunity for gender-based crimes. In this regard, an analysis is undertaken of the Special Court...

  8. Substituição de areia de quartzo por finos de gnaisse em massa cerâmica para telhas: teste industrial Replacing quartz sand for gnaisse fines waste into roofing tile body: industrial test

    Directory of Open Access Journals (Sweden)

    C. M. F. Vieira

    2008-12-01

    Full Text Available Foi avaliado o efeito da substituição de areia por um resíduo de beneficiamento de rocha ornamental, finos de gnaisse, em uma massa de cerâmica vermelha utilizada para fabricação de telhas. Foram preparadas telhas prensadas, do tipo "portuguesa", para queima a 900 ºC em forno industrial. As seguintes propriedades foram determinadas: retração linear, absorção de água e carga de ruptura na flexão. Além disso, avaliaram-se as características das matérias-primas e a plasticidade das composições por meio dos limites de Atterberg. Os resultados indicaram que a utilização de finos de gnaisse em substituição à areia possibilitou uma melhoria na trabalhabilidade/plasticidade da massa cerâmica e acarretou uma pequena redução na absorção de água das telhas. A resistência mecânica não se alterou, dentro da precisão estatística das medidas.The effect of replacing sand for gnaisse sawing waste into a red ceramic body used for roofing tile fabrication was evaluated. Pressed roofing tiles, "portuguese" style, were prepared before firing at 900 ºC in an industrial furnace. The following properties were evaluated: linear shrinkage, water absorption and load rupture strength. The plasticity of the elaborated compositions was determined by the Atterberg limits. The results show that the use of gnaisse fines replacing the sand, improved the workability of the ceramic body and promoted a slight decrease on the water absorption of the roofing tiles. The mechanical strength was not changed within the statistical error.

  9. A plea for unity, by Leon Lederman

    International Nuclear Information System (INIS)

    Anon.

    1986-01-01

    Last November saw the 30th anniversary of the discovery of the antiproton using the Bevatron at the University of California's Lawrence Berkeley Laboratory (then called the Radiation Laboratory). Fermilab Director Leon Lederman was in sparkling form at the banquet, where in his inimitable way he made an impassioned plea for scientific unity in these difficult times

  10. Explaining Violence in Sierra Leone's Civil War

    African Journals Online (AJOL)

    Explaining the violence of civil war is never a simple task for the scholar. In the case of the Sierra Leone, paradoxically, the task has in some ways been rendered more difficult by the sheer variety of compelling scholarship on the question. This paper seeks to identify the most useful of the explanations offered thus far, and ...

  11. GRAIN QUALITY IN SIERRA LEONE I

    African Journals Online (AJOL)

    Mimi

    and traders, as well as the marketing practices and aspirations for the improvement of rice grain quality in the ... smallholders who use manual traditional processing and handling practices like head portage for ... The study was a national market perception survey on the nature of rice grain quality in Sierra Leone with ...

  12. Sexual violence; post-conflict; Sierra Leone

    African Journals Online (AJOL)

    opperwjj

    and economic domains as a result of the conflict have evidently disempowered women and girls with a profound .... providers to explore views about sexual violence, focusing on community perceptions of the nature of ... Sierra Leone with conflicting views from victims, community leaders and service providers. Most health ...

  13. Sierra Leone Journal of Biomedical Research

    African Journals Online (AJOL)

    The Sierra Leone Journal of Biomedical Research publishes papers in all fields of Medicine and Allied Health Sciences including Basic Medical Sciences, Clinical Sciences, Dental Sciences, ... Survey of Current Practice of Labour Analgesia Among Obstetricians in Nigeria: Implications For Pain-free Labour Initiative.

  14. Establishing an enteric bacteria reference laboratory in Sierra Leone.

    Science.gov (United States)

    Chattaway, Marie Anne; Kamara, Abdul; Rhodes, Fay; Kaffeta, Konneh; Jambai, Amara; Alemu, Wondimagegnehu; Islam, Mohammed Sirajul; Freeman, Molly M; Welfare, William; Harding, Doris; Samba, Ahmed F; Abu, Musu; Kamanda, Sylvester; Grant, Kathie; Jenkins, Claire; Nair, Satheesh; Connell, Steve; Siorvanes, Lisa; Desai, Sarika; Allen, Collette; Frost, Margaret; Hughes, Daniel; Jeffrey, Zonya; Gill, Noel; Salter, Mark

    2014-06-09

    In 2012, Sierra Leone experienced its worst cholera outbreak in over 15 years affecting 12 of the country's 13 districts. With limited diagnostic capability, particularly in bacterial culture, the cholera outbreak was initially confirmed by microbiological testing of clinical specimens outside of Sierra Leone. During 2012 - 2013, in direct response to the lack of diagnostic microbiology facilities, and to assist in investigating and monitoring the cholera outbreak, diagnostic and reference services were established in Sierra Leone at the Central Public Health Reference Laboratory focusing specifically on isolating and identifying Vibrio cholerae and other enteric bacterial pathogens. Sierra Leone is now capable of confirming cholera cases by reference laboratory testing.

  15. The Introduction of Western Education in Sierra Leone and the ...

    African Journals Online (AJOL)

    The introduction of western education in the Sierra Leone colony led to the formation of a new class of people known in the Sierra Leone society as “the educated elite” or “the westernised elite.” The Sierra Leonean educated elite were well aware of the European culture and civilisation. They adopted a European dressing ...

  16. The Mathematical Works of Leon Battista Alberti

    CERN Document Server

    Williams, Kim; Wassell, Stephen R

    2010-01-01

    Leon Battista Alberti was an outstanding polymath of the fifteenth century, alongside Piero della Francesca and before Leonardo da Vinci. While his contributions to architecture and the visual arts are well known and available in good English editions, and much of his literary and social writings are also available in English, his mathematical works are not well represented in readily available, accessible English editions have remained accessible only to specialists. The four treatises included here - Ludi matematici, De Componendis Cifris, Elementi di pittura and De lunularum quadratura - ar

  17. Sands at Gusev Crater, Mars

    Science.gov (United States)

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

    2014-01-01

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

  18. Use of stone powder in concrete and mortar as an alternative of sand

    African Journals Online (AJOL)

    UFUOMA

    Stone powder produced from stone crushing zones appears as a problem for effective disposal. Sand is a common fine aggregate used in construction work as a fine aggregate. In this study, the main concern is to find an alternative of sand. Substitution of normal sand by stone powder will serve both solid.

  19. Use of stone powder in concrete and mortar as an alternative of sand

    African Journals Online (AJOL)

    Use of stone powder in concrete and mortar as an alternative of sand. ... Sand is a common fine aggregate used in construction work as a fine aggregate. In this study, the ... On the other hand, concrete from brick chip and stone powder produce higher compressive value from that of brick chip and normal sand concrete.

  20. Engineering of software the continuing contributions of Leon J. Osterweil

    CERN Document Server

    Tarr, Peri L

    2011-01-01

    Software engineering research can trace its roots to a small number of highly influential individuals including Prof. Leon J. Osterweil. This book assembles Prof. Osterweil's key publications as well as several new articles analyzing the impact of his work.

  1. International Marketing Strategy of Transformations LTD in Sierra Leone

    OpenAIRE

    Alam, Mohammed Touqeer

    2011-01-01

    The central idea of the report is to formulate an international marketing strategy for Transformations Ltd, a learning and development company based in UK for its entry in Sierra Leone market. The company wants to provide accredited British Leadership and Management qualification in Sierra Leone.\\ud \\ud The report uses theoretical framework for marketing analyses including internationalization models, entry mode, market segmentation, targeting, positioning and generic strategy. The report ado...

  2. Characteristics of SCC with Fly Ash and Manufactured Sand

    Science.gov (United States)

    Praveen Kumar, K.; Radhakrishna

    2016-09-01

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

  3. Variation of skin damage with flow rate associated with sand flow or stability in unconsolidated sand reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Tippie, D.B.; Kohlhaas, C.A.

    1974-01-01

    A semi-cylindrical sand-pack model of a cased-and-perforated completion was loaded with an overburden pressure and fluid flowed through the pack to simulate production. Flow rate was gradually increased in each test. Sand arches formed to stabilize sand movement. As reported previously by the same authors, arch size was a function of flow rate. Skin effect caused by arch formation, destruction, and size variation is also a function of flow rate. Minimum skin effects were noted for a particular flow rate. Potentiometric flow models were used to verify sand-pack results. Flow tests in a linear flow cell indicated a significant damage effect (permeability reduction) due to fines migration. The sand-pack completion model indicated that the fines migration and skin effect change are associated with sand instability.

  4. Soil Properties Database of Spanish Soils. Volume X.- Castilla-Leon (a): Leon, Zamora and Salamanca

    International Nuclear Information System (INIS)

    Trueba, C; Millan, R.; Schmid, T.; Lago, C.; Roquero, C; Magister, M.

    1999-01-01

    The soil vulnerability determines the sensitivity of the soil after an accidental radioactive contamination due to Cs-137 and Sr-90. The Departamento de Impacto Ambiental de la Energia of CIEMAT is carrying out an assessment of the radiological vulnerability of the different Spanish soils found on the Iberian Peninsula. This requires the knowledge of the soil properties for the various types of existing soils. In order to achieve this aim, a bibliographical compilation of soil profiles has been made to characterize the different soil types and create a database of their properties. Depending on the year of publication and the type of documentary source, the information compiled from the available bibliography is very heterogeneous. Therefore, an important effort has been made to normalize and process the information prior to its incorporation to the database. This volume presents the criteria applied to normalize and process the data as well as the soil properties of the various soil types belonging to the provinces of Leon, Zamora and Salamanca of the Comunidad Autonoma de Castilla-Leon. (Author) 41 refs

  5. Improvement of Engineering Properties of Igbokoda Standard Sand ...

    African Journals Online (AJOL)

    The coefficient of permeability “k” reduced with increasing strip size and strip concentration thereby modifying the hydraulic property of the sand from a fine sand range (1.30 x 10-5m/sec) to a silty sand range (4.95 x 10-6m/sec). The permeability test result further shows a direct relationship between the increasing shredded ...

  6. 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.

  7. 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.

  8. Critical State of Sand Matrix Soils

    Science.gov (United States)

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

    2014-01-01

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

  9. 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 L...

  10. Addressing gender-based violence in the Sierra Leone conflict ...

    African Journals Online (AJOL)

    The 11-year conflict had shattered the country, leaving more than a million people displaced and thousands of women coping with the aftermath of sexual violence. Then, in 1999, the Lomé Peace Accord in 1999 traded amnesty for peace and made provision for the establishment of the Sierra Leone Truth Commission.

  11. Measuring the impact of Ebola control measures in Sierra Leone.

    Science.gov (United States)

    Kucharski, Adam J; Camacho, Anton; Flasche, Stefan; Glover, Rebecca E; Edmunds, W John; Funk, Sebastian

    2015-11-17

    Between September 2014 and February 2015, the number of Ebola virus disease (EVD) cases reported in Sierra Leone declined in many districts. During this period, a major international response was put in place, with thousands of treatment beds introduced alongside other infection control measures. However, assessing the impact of the response is challenging, as several factors could have influenced the decline in infections, including behavior changes and other community interventions. We developed a mathematical model of EVD transmission, and measured how transmission changed over time in the 12 districts of Sierra Leone with sustained transmission between June 2014 and February 2015. We used the model to estimate how many cases were averted as a result of the introduction of additional treatment beds in each area. Examining epidemic dynamics at the district level, we estimated that 56,600 (95% credible interval: 48,300-84,500) Ebola cases (both reported and unreported) were averted in Sierra Leone up to February 2, 2015 as a direct result of additional treatment beds being introduced. We also found that if beds had been introduced 1 month earlier, a further 12,500 cases could have been averted. Our results suggest the unprecedented local and international response led to a substantial decline in EVD transmission during 2014-2015. In particular, the introduction of beds had a direct impact on reducing EVD cases in Sierra Leone, although the effect varied considerably between districts.

  12. Integration of learning technology in Sierra Leone's higher ...

    African Journals Online (AJOL)

    This article examined the scope and relevance of integrating technology in Sierra Leone's higher education systems. It discussed the general scope of technology provision in HEIs across the country, and the effectiveness of the National ICT Policy in enabling effective delivery of targets like the Vision 2025 Plan to be ...

  13. Young Women's Political Participation in Post-War Sierra Leone ...

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

    The end of the civil war in Sierra Leone in 2002 was facilitated in many ways by women through women's pro-democracy movements. These movements will continue to be pivotal in the gradual strengthening of democratic governance structures. Irrespective of the immense barriers that they face, women of all ages have ...

  14. Sierra Leone Journal of Biomedical Research Original Article

    African Journals Online (AJOL)

    J. M. Lamin

    During the Ebola outbreak in Sierra Leone, there has been a strong suspicion that people avoided the premises for drug administration such as hospitals, clinics and Community Health Centres. Health care service providers were terrified and reluctant to deliver services at the initial stage of the epidemic because of fear of ...

  15. An accidental sect: how war made belief in Sierra Leone

    NARCIS (Netherlands)

    Richards, P.

    2006-01-01

    Idealists consider beliefs cause wars. Realists consider wars cause beliefs. The war in Sierra Leone offers some scope to test between these two views. The main rebel faction, the Revolutionary United Front (RUF) was, sociologically speaking, an accidental sect. It lost its original ideologues at an

  16. Indigenous knowledge in cattle breeding in Sierra Leone | Abdul ...

    African Journals Online (AJOL)

    This study was conducted in order to document and preserve valuable indigenous knowledge in cattle breeding and production under traditional cattle production system in Sierra Leone. Data were collected from thirty (30) cattle farms from three locations: Gbindi (16 farms), Sackelereh (7 farms), and Flamansa (7 farms) in ...

  17. Young Women's Political Participation in Post-War Sierra Leone ...

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

    ... political parties, civil society and kin-based social organizations can be influenced to advance women's choices and entitlements as citizens, including through increased representation. The end of the civil war in Sierra Leone in 2002 was facilitated in many ways by women through women's pro-democracy movements.

  18. Young Women's Political Participation in Post-War Sierra Leone ...

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

    Young Women's Political Participation in Post-War Sierra Leone. IDRC's Democratic Governance, Women's Rights and Gender Equality initiative is supporting a body of comparative research on whether and how democratic processes and institutions are responding to women's rights and gender equality. The projects ...

  19. Power in Practice: Trade Union Education in Sierra Leone

    Science.gov (United States)

    Stirling, John

    2013-01-01

    This article presents an analysis of the development of a trade union education program in Sierra Leone in the geo-historical context of British colonialism. It places the argument in relation to the contradictory trends of trade unionism more generally and alongside their antagonistic cooperation with capitalism. It discusses the limits and…

  20. Assessing unmet anaesthesia need in Sierra Leone: a secondary ...

    African Journals Online (AJOL)

    Surgical patients' families often must provide funds for fuel for the hospital's electricity generator during their relative's surgery.19,21. This analysis provides guidance as to rational and ef- ficient training of personnel, and equipment purchase and distribution. Fifty-three per cent of unmet surgi- cal need in Sierra Leone would ...

  1. Military Interventions in Sierra Leone: Lessons from a Failed State

    National Research Council Canada - National Science Library

    Woods, Larry J; Reese, Timothy R

    2008-01-01

    This study by Larry J. Woods and Colonel Timothy R. Reese analyzes the massive turmoil afflicting the nation of Sierra Leone, 1993-2002, and the efforts by a variety of outside forces to bring lasting stability to that small country...

  2. Health complications of female genital mutilation in Sierra Leone

    Directory of Open Access Journals (Sweden)

    Bjälkander O

    2012-07-01

    Full Text Available Owolabi Bjälkander,1 Laurel Bangura,2 Bailah Leigh,3 Vanja Berggren,1 Staffan Bergström,1 Lars Almroth11Division of Global Health, Department of Public Health, Karolinska Institutet, Stockholm, Sweden; 2Inter Africa Committee, Sierra Leone; 3Department of Community Health, College of Medicine and Allied Health Sciences, University of Sierra Leone, Sierra LeoneAbstract: Sierra Leone has one of the highest rates of female genital mutilation (FGM in the world, and yet little is known about the health consequences of the practice.Purpose: To explore whether and what kind of FGM-related health complications girls and women in Sierra Leone experience, and to elucidate their health care-seeking behaviors.Patients and methods: A feasibility study was conducted to test and refine questionnaires and methods used for this study. Thereafter, a cross-section of girls and women (n = 258 attending antenatal care and Well Women Clinics in Bo Town, Bo District, in the southern region and in Makeni Town, Bombali District, in the northern region of Sierra Leone were randomly selected. Participants answered interview-administrated pretested structured questionnaires with open-ended-questions, administrated by trained female personnel.Results: All respondents had undergone FGM, most between 10 and 14 years of age. Complications were reported by 218 respondents (84.5%, the most common ones being excessive bleeding, delay in or incomplete healing, and tenderness. Fever was significantly more often reported by girls who had undergone FGM before 10 years of age compared with those who had undergone the procedure later. Out of those who reported complications, 187 (85.8% sought treatment, with 89 of them visiting a traditional healer, 75 a Sowei (traditional circumciser, and 16 a health professional.Conclusion: The high prevalence rate of FGM and the proportion of medical complications show that FGM is a matter for public health concern in Sierra Leone. Girls who

  3. 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....

  4. Lassa fever in post-conflict sierra leone.

    Directory of Open Access Journals (Sweden)

    Jeffrey G Shaffer

    2014-03-01

    Full Text Available Lassa fever (LF, an often-fatal hemorrhagic disease caused by Lassa virus (LASV, is a major public health threat in West Africa. When the violent civil conflict in Sierra Leone (1991 to 2002 ended, an international consortium assisted in restoration of the LF program at Kenema Government Hospital (KGH in an area with the world's highest incidence of the disease.Clinical and laboratory records of patients presenting to the KGH Lassa Ward in the post-conflict period were organized electronically. Recombinant antigen-based LF immunoassays were used to assess LASV antigenemia and LASV-specific antibodies in patients who met criteria for suspected LF. KGH has been reestablished as a center for LF treatment and research, with over 500 suspected cases now presenting yearly. Higher case fatality rates (CFRs in LF patients were observed compared to studies conducted prior to the civil conflict. Different criteria for defining LF stages and differences in sensitivity of assays likely account for these differences. The highest incidence of LF in Sierra Leone was observed during the dry season. LF cases were observed in ten of Sierra Leone's thirteen districts, with numerous cases from outside the traditional endemic zone. Deaths in patients presenting with LASV antigenemia were skewed towards individuals less than 29 years of age. Women self-reporting as pregnant were significantly overrepresented among LASV antigenemic patients. The CFR of ribavirin-treated patients presenting early in acute infection was lower than in untreated subjects.Lassa fever remains a major public health threat in Sierra Leone. Outreach activities should expand because LF may be more widespread in Sierra Leone than previously recognized. Enhanced case finding to ensure rapid diagnosis and treatment is imperative to reduce mortality. Even with ribavirin treatment, there was a high rate of fatalities underscoring the need to develop more effective and/or supplemental treatments for

  5. Lassa Fever in Post-Conflict Sierra Leone

    Science.gov (United States)

    Hartnett, Jessica N.; Levy, Danielle C.; Yenni, Rachael E.; Moses, Lina M.; Fullah, Mohammed; Momoh, Mambo; Fonnie, Mbalu; Fonnie, Richard; Kanneh, Lansana; Koroma, Veronica J.; Kargbo, Kandeh; Ottomassathien, Darin; Muncy, Ivana J.; Jones, Abigail B.; Illick, Megan M.; Kulakosky, Peter C.; Haislip, Allyson M.; Bishop, Christopher M.; Elliot, Deborah H.; Brown, Bethany L.; Zhu, Hu; Hastie, Kathryn M.; Andersen, Kristian G.; Gire, Stephen K.; Tabrizi, Shervin; Tariyal, Ridhi; Stremlau, Mathew; Matschiner, Alex; Sampey, Darryl B.; Spence, Jennifer S.; Cross, Robert W.; Geisbert, Joan B.; Folarin, Onikepe A.; Happi, Christian T.; Pitts, Kelly R.; Geske, F. Jon; Geisbert, Thomas W.; Saphire, Erica Ollmann; Robinson, James E.; Wilson, Russell B.; Sabeti, Pardis C.; Henderson, Lee A.; Khan, S. Humarr; Bausch, Daniel G.; Branco, Luis M.; Garry, Robert F.

    2014-01-01

    Background Lassa fever (LF), an often-fatal hemorrhagic disease caused by Lassa virus (LASV), is a major public health threat in West Africa. When the violent civil conflict in Sierra Leone (1991 to 2002) ended, an international consortium assisted in restoration of the LF program at Kenema Government Hospital (KGH) in an area with the world's highest incidence of the disease. Methodology/Principal Findings Clinical and laboratory records of patients presenting to the KGH Lassa Ward in the post-conflict period were organized electronically. Recombinant antigen-based LF immunoassays were used to assess LASV antigenemia and LASV-specific antibodies in patients who met criteria for suspected LF. KGH has been reestablished as a center for LF treatment and research, with over 500 suspected cases now presenting yearly. Higher case fatality rates (CFRs) in LF patients were observed compared to studies conducted prior to the civil conflict. Different criteria for defining LF stages and differences in sensitivity of assays likely account for these differences. The highest incidence of LF in Sierra Leone was observed during the dry season. LF cases were observed in ten of Sierra Leone's thirteen districts, with numerous cases from outside the traditional endemic zone. Deaths in patients presenting with LASV antigenemia were skewed towards individuals less than 29 years of age. Women self-reporting as pregnant were significantly overrepresented among LASV antigenemic patients. The CFR of ribavirin-treated patients presenting early in acute infection was lower than in untreated subjects. Conclusions/Significance Lassa fever remains a major public health threat in Sierra Leone. Outreach activities should expand because LF may be more widespread in Sierra Leone than previously recognized. Enhanced case finding to ensure rapid diagnosis and treatment is imperative to reduce mortality. Even with ribavirin treatment, there was a high rate of fatalities underscoring the need to

  6. 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...

  7. Deforestation in Gola Forest Region, Sierra Leone: Geospatial Evidence and a Rice Farmer's Expected Utility Analysis

    Science.gov (United States)

    Abu-Kpawoh, John Christian

    classification suggests that the community forests in the Gola region (seven Gola chiefdoms) are losing forest cover at an annual rate of 4.18%, while the Park is increasing its forest cover at a rate of 0.03% per year. Even though the park appears to increase its forest cover, classification details reveal encroachment to just within the park from the boundary, compromising the quality and integrity of the park. Adapting the theoretical poaching model in Messer (2010), we model the farmer's decision to engage in a profitable illegal farming (deforestation), as a function of expected returns and the cost of punishment. In this context, the farmer decides on the amount of hectares to illegally cultivate subject to a time constraint, and taking the risk of being caught as given, the latter being function of government law enforcement. We develop two cost studies, one for legal and one for illegal rice cultivation, and obtain the revenue parameters. Revenue parameters are validated through reports of the Planning, Evaluation, Monitoring and Statistics Division (PEMSD) of Sierra Leone's Ministry of Agriculture, Forestry & Food Security. Our simulation results suggest that increasing the amount of fines imposed and/or lengthy imprisonment is not a feasible or realistic policy to dis-incentivize deforestation and illegal farming. The probability of being caught committing crime and the fine have to be both unrealistically large to deter a risk neutral farmer. Another policy relates to reducing the net-benefit from illegal farming, and increasing the risk of being caught. We find that a policy that increases the risk is most effective in reducing illegal farming with minimal policy change. We then compare the potential of these policies in reducing the incentives to illegally farm with the current policy consisting solely of law enforcement. We expect the results to be relevant to the authorities in Sierra Leone and other countries facing the responsibility of safeguarding natural

  8. EFFECT OF HCL CONCENTRATION ON NORMAL CONCRETE AND ADMIXTURED CONCRETE MADE WITH AND WITHOUT MANUFACTURED SAND

    OpenAIRE

    K. Pradeep*, K. Ramudu

    2017-01-01

    Concrete is considered to be the most widely used and versatile material of construction all over the world. One of the important ingredients of conventional concrete is natural sand or river sand, which is on the verge of exhausting due to abundant usage. In India, the conventional concrete is produced by using natural sand obtained from riverbeds as fine aggregate. However, due to the increased use of concrete in almost all types of construction works, the demand of natural or river sand ha...

  9. Permeability Tests on Silkeborg Sand No. 0000

    DEFF Research Database (Denmark)

    Lund, Willy; Jakobsen, Kim Parsberg

    on the characteristics of the soil matrix, the permeability is determined for different void ratios. All tests are performed on reconstituted specimens of Silkeborg Sand No. 0000. The permeability is determined by use of a falling head apparatus. The apparatus, test procedures and the analysis method are described......The flow through porous media plays an important role in various engineering disciplines, as for example in ground water hydrology and soil mechanics. In the present study the permeability is determined for a fine, saturated sand. As the flow through a porous media strongly depends...

  10. Permeability Tests on Eastern Scheldt Sand

    DEFF Research Database (Denmark)

    Jakobsen, Kim Parsberg

    on the characteristics of the soil matrix, the permeability is determined for different void ratios. All tests are performed on reconstituted specimens of Eastern Scheldt Sand. The permeability is determined by use of a falling head apparatus. Finally the test results are briefly summarised and a relationship between......The flow through porous media plays an important role in various engineering disciplines, as for example in ground water hydrology and soil mechanics. In the present study the permeability is determined for a fine, saturated sand. As the flow through a porous media strongly depends...

  11. Indirect determination of particle shape of fine aggregate.

    Science.gov (United States)

    1973-01-01

    Three methods developed by various agencies for measuring indirectly the particle shapes of fine aggregates were used along with a visual classification procedure to study aggregates from eight commercial sources along with a reference sand. The meth...

  12. Effect of substrate size on sympatric sand darter benthic habitat preferences

    Science.gov (United States)

    Thompson, Patricia A.; Welsh, Stuart A.; Rizzo, Austin A.; Smith, Dustin M.

    2017-01-01

    The western sand darter, Ammocrypta clara, and the eastern sand darter, A. pellucida, are sand-dwelling fishes that have undergone range-wide population declines, presumably owing to habitat loss. Habitat use studies have been conducted for the eastern sand darter, but literature on the western sand darter remains sparse. To evaluate substrate selection and preference, western and eastern sand darters were collected from the Elk River, West Virginia, one of the few remaining rivers where both species occur sympatrically. In the laboratory, individuals were given the choice to bury into five equally available and randomly positioned substrates ranging from fine sand to granule gravel (0.12–4.0 mm). The western sand darter selected for coarse and medium sand, while the eastern sand darter was more of a generalist selecting for fine, medium, and coarse sand. Substrate selection was significantly different (p = 0.02) between species in the same environment, where the western sand darter preferred coarser substrate more often compared to the eastern sand darter. Habitat degradation is often a limiting factor for many species of rare freshwater fish, and results from this study suggest that western and eastern sand darters may respond differently to variations in benthic substrate composition.

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

    Science.gov (United States)

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

    2015-04-01

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

  14. Assessment of fine aggregates from different sources in Ibadan and ...

    African Journals Online (AJOL)

    Assessment of natural sand being used as fine aggregate for concrete production in Ibadan and its environs was carried out. Ten sources (F1 – F10) were selected for the study; four (F5, F6, F7, F8) were river sand sources while six (F1, F2, F3, F4, F9, F10) were burrow pit sand sources. Samples from each source were ...

  15. Assessment of Fine Aggregates from Different Sources in Ibadan ...

    African Journals Online (AJOL)

    OLUWASOGO

    friable particles, amount of materials passing 75μm and organic impurities adopting ASTM standard procedures. Results revealed that sand ... sand are majorly used as fine aggregate materials for concrete production ... 2Department of Civil Engineering, Faculty of Engineering, Adeleke University, P.M.B. 250, Ede, Nigeria.

  16. Anne Fine

    Directory of Open Access Journals (Sweden)

    Philip Gaydon

    2015-04-01

    Full Text Available An interview with Anne Fine with an introduction and aside on the role of children’s literature in our lives and development, and our adult perceptions of the suitability of childhood reading material. Since graduating from Warwick in 1968 with a BA in Politics and History, Anne Fine has written over fifty books for children and eight for adults, won the Carnegie Medal twice (for Goggle-Eyes in 1989 and Flour Babies in 1992, been a highly commended runner-up three times (for Bill’s New Frock in 1989, The Tulip Touch in 1996, and Up on Cloud Nine in 2002, been shortlisted for the Hans Christian Andersen Award (the highest recognition available to a writer or illustrator of children’s books, 1998, undertaken the positon of Children’s Laureate (2001-2003, and been awarded an OBE for her services to literature (2003. Warwick presented Fine with an Honorary Doctorate in 2005. Philip Gaydon’s interview with Anne Fine was recorded as part of the ‘Voices of the University’ oral history project, co-ordinated by Warwick’s Institute of Advanced Study.

  17. Optimizing the Moulding Properties of Recycled Ilaro Silica Sand

    Directory of Open Access Journals (Sweden)

    Davies Oladayo FOLORUNSO

    2011-12-01

    Full Text Available Effect of varying binders (bentonite and dextrin and water on the properties of recycled foundry sand made from silica sand mined from Ilaro Silica sand deposit in Ogun State Nigeria and have been used in several cycles for production of cast iron was examined. The used sand was washed in hot water, dried and the sieved for grain distribution. Varying bentonite and dextrin contents were added together with water to portions of the silica sand and thoroughly mixed. The moulding sand properties (permeability, green strength, compatibility, shatter index and moisture content of the recycled foundry sand were determined. It was observed that the recycled Ilaro sand (after several cycle of usage has grain Fineness Index (GFI of 50 and that it can still be reused by minimum addition of binders. It was concluded that the optimum green strength and permeability for the recycled sand was achieved when 12g of bentonite, 8g of dextrin and 12cm3 of water were added to 200g of recycled sand.

  18. Properties of dune sand concrete containing coffee waste

    Directory of Open Access Journals (Sweden)

    Mohamed Guendouz

    2018-01-01

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

  19. Identity with Jesus Christ: the case of Leon Gabor.

    Science.gov (United States)

    Capps, Donald

    2010-12-01

    From July 1, 1959 to August 15, 1961, Milton Rokeach studied three male patients at Ypsilanti State Hospital who believed that they were Jesus Christ. They met regularly together with Rokeach and his research staff, a procedure designed to challenge their delusional systems. He believed that Leon Gabor, the youngest of the three, would be the most likely to abandon his delusional beliefs. Instead, Leon met the challenges that the procedure posed by creative elaborations of his delusional system, especially through the adoption of a new name that gave the initial appearance of the abandonment of his Christ identity but in fact drew on aspects of the real Jesus Christ's identity that were missing from his earlier self-representation.

  20. Hydrographic and chemical observations in the Sierra Leone River estuary

    International Nuclear Information System (INIS)

    Koske, P.H.; Weiler, K.

    1979-01-01

    Hydrographic and chemical observations in the Sierra Leone River estuary are reported, a West-African river in the tropics. Because of the typical change between rainy season in the sommer months and dry season in winter time the research work has been adapted to these semi-annual changes. The collected data and results are given and discussed under this aspect of the seasonal fluctuations. (orig.) [de

  1. Health complications of female genital mutilation in Sierra Leone

    Science.gov (United States)

    Bjälkander, Owolabi; Bangura, Laurel; Leigh, Bailah; Berggren, Vanja; Bergström, Staffan; Almroth, Lars

    2012-01-01

    Sierra Leone has one of the highest rates of female genital mutilation (FGM) in the world, and yet little is known about the health consequences of the practice. Purpose To explore whether and what kind of FGM-related health complications girls and women in Sierra Leone experience, and to elucidate their health care-seeking behaviors. Patients and methods A feasibility study was conducted to test and refine questionnaires and methods used for this study. Thereafter, a cross-section of girls and women (n = 258) attending antenatal care and Well Women Clinics in Bo Town, Bo District, in the southern region and in Makeni Town, Bombali District, in the northern region of Sierra Leone were randomly selected. Participants answered interview-administrated pretested structured questionnaires with open- ended-questions, administrated by trained female personnel. Results All respondents had undergone FGM, most between 10 and 14 years of age. Complications were reported by 218 respondents (84.5%), the most common ones being excessive bleeding, delay in or incomplete healing, and tenderness. Fever was significantly more often reported by girls who had undergone FGM before 10 years of age compared with those who had undergone the procedure later. Out of those who reported complications, 187 (85.8%) sought treatment, with 89 of them visiting a traditional healer, 75 a Sowei (traditional circumciser), and 16 a health professional. Conclusion The high prevalence rate of FGM and the proportion of medical complications show that FGM is a matter for public health concern in Sierra Leone. Girls who undergo FGM before 10 years of age seem to be more vulnerable to serious complications than those who are older at the time of FGM. It is important that health care personnel are aware of, and look for possible complications from FGM, and encourage girls and women to seek medical care for their problems. PMID:22870046

  2. Seroprevalence of Ebola virus infection in Bombali District, Sierra Leone

    Directory of Open Access Journals (Sweden)

    Nadege Goumkwa Mafopa

    2017-12-01

    Full Text Available A serosurvey of anti-Ebola Zaire virus nucleoprotein IgG prevalence was carried out among Ebola virus disease survivors and their Community Contacts in Bombali District, Sierra Leone. Our data suggest that the specie of Ebola virus (Zaire responsible of the 2013-2016 epidemic in West Africa may cause mild or asymptomatic infection in a proportion of cases, possibly due to an efficient immune response.

  3. Judicial contributions of the Sierra Leone tribunal to the development of international criminal law

    OpenAIRE

    Jalloh, C.C.

    2016-01-01

    This dissertation considers whether the Special Court for Sierra Leone (“SCSL”), which was established jointly through an unprecedented bilateral treaty between the United Nations (“UN”) and Sierra Leone in 2002, has made jurisprudential contributions to the development of international criminal law. The work opens with an examination of the outbreak of a notoriously brutal civil war in Sierra Leone which lasted between March 1991 and January 2002 and led to the deaths of approximately 75,000...

  4. Reducing CO2 emissions in Sierra Leone and Ghana

    International Nuclear Information System (INIS)

    Davidson, O.

    1991-01-01

    With soring population growth rates and minimal economic growth, the nations of Africa are afflicted with innumerable problems. Why then should Africa's developing countries worry about CO 2 emissions? First, because agricultural activities form the backbone of most African economies; thus, these nations may be particularly vulnerable to the negative impacts of climate change. Second, acting to reduce carbon emissions will bring about more efficient energy use. All of Africa could benefit from the improved use of energy. Finally, the accumulation of CO 2 in the atmosphere is a global problem with individual solutions; in order to reduce international emissions, all countries, including those in Africa, must contribute. Typical of many African countries, Ghana and Sierra Leone have among the lowest levels of energy demand per capita across the globe. primary energy demand per capita in these two West African nations equals about one quarter of the world's average and about one twentieth of the US average. This work summarizes the results of two long-term energy use and carbon emissions scenarios for Sierra Leone and Ghana. In the high emissions (HE) scenario for 2025, policy changes focused on galvanizing economic growth lead to significant increases in energy use and carbon emissions in Ghana and Sierra Leone between 1985 and 2025. In the low emissions (LE) scenario, the implementation of policies aimed specifically at curtailing CO 2 emissions significantly limits the increase in carbon in both nations by 2025

  5. Enhanced microbubbles assisted cleaning of diesel contaminated sand.

    Science.gov (United States)

    Agarwal, Ashutosh; Liu, Yu

    2017-11-15

    In this article, we investigated the effect of low intensity pulsed ultrasound (US), temperature and salinity on cleaning efficacy of fine bubbles with diameter diesel contaminated sands. About 47% and 76% diesel removal was achieved from 10% (w/w) diesel contaminated fine and medium sands respectively, after 30min treatment with 40kHz low intensity intermittent pulsed US together with MBs in contrast to 41% and 68% diesel removal while treatment with MBs alone. The effect of high temperature was found to be prominent during the initial stages of cleaning. In addition, MBs generated in 599mM saline water efficiently removed 85% diesel from fine sand within 30min in contrast to only 41% diesel removal with MBs in fresh water. This study provides evidence for developing highly efficient MBs based chemical free technology for diesel contaminated sediments. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Hardware Support for Fine-Grain Multi-Threading in LEON3

    Czech Academy of Sciences Publication Activity Database

    Daněk, Martin; Kafka, Leoš; Kohout, Lukáš; Sýkora, Jaroslav

    2011-01-01

    Roč. 4, č. 1 (2011), s. 27-34 ISSN 1844-9689 R&D Projects: GA MŠk 7E08013 Grant - others:European Commission(BE) FP7- ICT -215216 Keywords : multithreading * microthreading * SPARC * microarchitecture * FPGA Subject RIV: JC - Computer Hardware ; Software http://library.utia.cas.cz/separaty/2011/ZS/danek-0380861.pdf

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

    Science.gov (United States)

    Katra, Itzhak; Scheidt, Stephen; Lancaster, Nicholas

    2009-04-01

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

  8. 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.

  9. 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.

  10. Singing Sand Dunes

    Indian Academy of Sciences (India)

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

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

    OpenAIRE

    Marius Dan Gavriletea

    2017-01-01

    Sand is an indispensable natural resource for any society. Despite society’s increasing dependence on sand, there are major challenges that this industry needs to deal with: limited sand resources, illegal mining, and environmental impact of sand mining. The purpose of this paper is twofold: to present an overview of the sand market, highlighting the main trends and actors for production, export and import, and to review the main environmental impacts associated with sand exploitation process...

  12. Alcohol and drugs in post-war Sierra Leone | Bøås | African Journal ...

    African Journals Online (AJOL)

    The kind of social stress that a civil war expose the population to makes it easy to assume that an increased level of alcohol and drug abuse should be observable in post-war Sierra Leone. This is, however, not the case. As this study reveals, the pattern of alcohol and drug consumption in Sierra Leone. This is, however, not ...

  13. To fight or to farm? Agrarian dimensions of the Mano River conflicts (Liberia and Sierra Leone)

    NARCIS (Netherlands)

    Richards, P.

    2005-01-01

    The wars in Liberia and Sierra Leone have been linked to the condition of urbanized youth. Recent research in southeastern Sierra Leone and northwestern Liberia suggests the rural context is of greater significance. The fighting was mainly in rural areas, involved mainly rural youth, and adapted

  14. Assessment of Anemia Knowledge, Attitudes and Behaviors among Pregnant Women in Sierra Leone

    Science.gov (United States)

    M'Cormack, Fredanna A. D.; Drolet, Judy C.

    2012-01-01

    Introduction: Iron deficiency anemia prevalence of pregnant Sierra Leone women currently is reported to be 59.7%. Anemia is considered to be a direct cause of 3-7% of maternal deaths and an indirect cause of 20-40% of maternal deaths. This study explores knowledge, attitudes, and behaviors of urban pregnant Sierra Leone women regarding anemia.…

  15. Judicial contributions of the Sierra Leone tribunal to the development of international criminal law

    NARCIS (Netherlands)

    Jalloh, C.C.

    2016-01-01

    This dissertation considers whether the Special Court for Sierra Leone (“SCSL”), which was established jointly through an unprecedented bilateral treaty between the United Nations (“UN”) and Sierra Leone in 2002, has made jurisprudential contributions to the development of international criminal

  16. Genotypic differences in yield formation, phosphorus utilization and nitrogen fixation by cowpeas in Sierra Leone

    International Nuclear Information System (INIS)

    Amara, D.S.

    1996-01-01

    Available phosphorus (P) and nitrogen (NP) generally occur in very low amounts in soils of the tropics and subtropics. Under such conditions, most crops would require the addition of N and P fertilizer. This is not possible for small-scale farmers who cannot afford or have limited access to fertilizers, and therefore depend on low-input cropping systems. The selection of cultivars adapted to low soil nutrient conditions would sustain the production levels of subsistence farmers. Experiments were therefore conducted over a five-year period to identify cowpea cultivars with high phosphorus use efficiency and nitrogen fixation. Two of such cultivars-IT86D-1010 and IT86D-719 have been identified. Root morphological characteristics such as root length, root fineness and vesicular-arbuscular mycorrhizae are responsible for high P uptake and use efficiency. Multilocational testing of the cultivars showed that they cannot do well in areas with low rainfall. They have been distributed to farmers through the extension services for large scale production in southern Sierra Leone. (author). 28 refs, 4 figs, 6 tabs

  17. Petrochemicals from oil sands

    International Nuclear Information System (INIS)

    Du Plessis, M.P.; McCann, T.J.

    2003-01-01

    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

  18. REMEDIATION OF LEON WATER FLOOD, BUTLER COUNTY, KANSAS

    Energy Technology Data Exchange (ETDEWEB)

    M.L. Korphage; Kelly Kindscher; Bruce G. Langhus

    2001-11-26

    The Leon Water Flood site has undergone one season of soil amendments and growth of specialized plants meant to colonize and accelerate the remediation of the salt-impacted site. The researchers characterized the impacted soil as to chemistry, added soil amendments, and planted several species of seedlings, and seeded the scarred areas. After the first growing season, the surface soil was again characterized and groundcover was also characterized. While plant growth was quite meager across the area, soil chemistry did improve over most of the two scars.

  19. Novel Retinal Lesion in Ebola Survivors, Sierra Leone, 2016.

    Science.gov (United States)

    Steptoe, Paul J; Scott, Janet T; Baxter, Julia M; Parkes, Craig K; Dwivedi, Rahul; Czanner, Gabriela; Vandy, Matthew J; Momorie, Fayiah; Fornah, Alimamy D; Komba, Patrick; Richards, Jade; Sahr, Foday; Beare, Nicholas A V; Semple, Malcolm G

    2017-07-01

    We conducted a case-control study in Freetown, Sierra Leone, to investigate ocular signs in Ebola virus disease (EVD) survivors. A total of 82 EVD survivors with ocular symptoms and 105 controls from asymptomatic civilian and military personnel and symptomatic eye clinic attendees underwent ophthalmic examination, including widefield retinal imaging. Snellen visual acuity was Ebola virus, permitting cataract surgery. A novel retinal lesion following the anatomic distribution of the optic nerve axons occurred in 14.6% (97.5% CI 7.1%-25.6%) of EVD survivors and no controls, suggesting neuronal transmission as a route of ocular entry.

  20. Fine chemistry

    International Nuclear Information System (INIS)

    Laszlo, P.

    1988-01-01

    The 1988 progress report of the Fine Chemistry laboratory (Polytechnic School, France) is presented. The research programs are centered on the renewal of the organic chemistry most important reactions and on the invention of new, highly efficient and highly selective reactions, by applying low cost reagents and solvents. An important research domain concerns the study and fabrication of new catalysts. They are obtained by means of the reactive sputtering of the metals and metal oxydes thin films. The Monte Carlo simulations of the long-range electrostatic interaction in a clay and the obtention of acrylamides from anhydrous or acrylic ester are summarized. Moreover, the results obtained in the field of catalysis are also given. The published papers and the congress communications are included [fr

  1. Fine-Grained Concrete of Composite Binder

    Science.gov (United States)

    Fediuk, R.; Pak, A.; Kuzmin, D.

    2017-11-01

    The article is devoted to the application of industrial wastes for the production of high-quality concretes with specified characteristics. The composite binders with low water demand (BLW) have been developed. Their strength is approximately twice the strength of the initial cement, and dilute BLW with 50 - 70% of the ground slag or quartz sand in their composition provide the same strength as the original Portland cement. It was proved that the quartzite sand screening can be used as a filler in the preparation of fine-grained concretes.

  2. Recycled sand in lime-based mortars.

    Science.gov (United States)

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

    2014-12-01

    The increasing awareness of the society about safe guarding heritage buildings and at the same time protecting the environment promotes strategies of combining principles of restoration with environmentally friendly materials and techniques. Along these lines, an experimental program was carried out in order to investigate the possibility of producing repair, lime-based mortars used in historic buildings incorporating secondary materials. The alternative material tested was recycled fine aggregates originating from mixed construction and demolition waste. Extensive tests on the raw materials have been performed and mortar mixtures were produced using different binding systems with natural, standard and recycled sand in order to compare their mechanical, physical and microstructure properties. The study reveals the improved behavior of lime mortars, even at early ages, due to the reaction of lime with the Al and Si constituents of the fine recycled sand. The role of the recycled sand was more beneficial in lime mortars rather than the lime-pozzolan or lime-pozzolan-cement mortars as a decrease in their performance was recorded in the latter cases due to the mortars' structure. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Sand and Gravel Deposits

    Data.gov (United States)

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

  4. 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...

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

    NARCIS (Netherlands)

    Homan, T.A.M.; Mudde, R.F.; Lohse, Detlef; van der Meer, Roger M.

    2015-01-01

    When a ball is dropped in fine very loose sand, a splash and subsequently a jet are observed above the bed, followed by a granular eruption. To directly and quantitatively determine what happens inside the sand bed, high-speed X-ray tomography measurements are carried out in a custom-made set-up

  6. Managing Fine Sediment in Regulated Rivers

    Science.gov (United States)

    Schmidt, J. C.

    2015-12-01

    A paradigm useful in managing dams and diversions is that the combined effects of changing flow regime and sediment supply perturb regulated rivers into sediment deficit or sediment surplus. In the U.S. Southwest, large dams constructed on interregional rivers typically create sediment deficit segments >100 km long. Further downstream, sediment surplus may occur if desert tributaries deliver sufficient amounts of fine sediment, such as parts of the Rio Grande, lower Green River, and Colorado River delta. Sediment surplus also occurs on most smaller regional rivers. The protocols for managing rivers perturbed into sediment deficit have been refined for the Colorado River downstream from Glen Canyon Dam but are nonetheless challenged by externally determined water-supply agreements that require annual water deliveries that sometimes occur when there has been little tributary resupply. Virtually all of the naturally supplied sand to the depleted, 100-km long Marble Canyon comes from the Paria River. The sand delivery rate since 2012 was sufficiently large to trigger short-duration controlled floods under the High Flow Experiment (HFE) Protocol. The sand mass balance of Marble Canyon since 2012 when the HFE Protocol was adopted was positive due to the combination of relatively large sand delivery from the Paria River and average total annual flows. Large total annual flows have the potential to export large amounts of sand and create a negative sand mass balance. Despite the challenge of managing a scarce and highly variable sand supply and occasional years of large reservoir releases, the long-term (2006-2015) sand mass balance for the upstream half of Marble Canyon is indeterminant and is positive for the downstream half of Marble Canyon. The apparent success of managing sand in Grand Canyon under deficit conditions suggests that fine sediment management protocols might be developed for other regulated rivers. Implementation would require establishment of networks of

  7. Laryngologist Leon Zamenhof--brother of Dr. Esperanto.

    Science.gov (United States)

    Wincewicz, Andrzej; Sulkowska, Mariola; Musiatowicz, Marcin; Sulkowski, Stanislaw

    2009-06-01

    To reconstruct the biography of the Polish otorhinolaryngologist Leon Zamenhof (1875-1934), a brother of Ludwik Zamenhof, who is famous for invention of the international language Esperanto. Biographical information was collected from pre-World War II resources. Zamenhof developed several important new forms of treatment to help the hearing impaired. Zamenhof was especially interested in the education of deaf children and the therapy necessary to facilitate their integration into society. His significant achievements were a phonetic method of therapy for the hearing impaired and an automatic device for ear insufflation that was considered indispensable in the management of pyorrhea. In addition, Zamenhof initiated various forms of social support among physicians within the medical community of Warsaw, Poland; made health care available to children with hearing impairments; and organized a Jewish school for deaf children. Zamenhof tried to change public attitudes toward deafness, working to promote the integration of the deaf into wider society. He also translated Polish literature into Esperanto. With similar aims to his brother Ludwik, Leon Zamenhof strived to enhance and broaden communication among people who could not hear and to persuade people to change their attitudes about deafness.

  8. Soil Properties Database of Spanish Soils. Volume X.- Castilla-Leon (a): Leon, Zamora and Salamanca; Base de datos de propiedades edafologicas de los suelos espanoles. volumen X. Castilla-Leon (a): Leon, Zamora y Salamanca

    Energy Technology Data Exchange (ETDEWEB)

    Trueba, C.; Millan, R.; Schmid, T.; Lago, C. [CIEMAT. Madrid (Spain); Roquero, C.; Magister, M. [UPM. Madrid (Spain)

    1999-09-01

    The soil vulnerability determines the sensitivity of the soil after an accidental radioactive contamination due to Cs-137 and Sr-90. The Departamento de Impacto Ambiental de la Energia of CIEMAT is carrying out an assessment of the radiological vulnerability of the different Spanish soils found on the Iberian Peninsula. This requires the knowledge of the soil properties for the various types of existing soils. In order to achieve this aim, a bibliographical compilation of soil profiles has been made to characterize the different soil types and create a database of their properties. Depending on the year of publication and the type of documentary source, the information compiled from the available bibliography is very heterogeneous. Therefore, an important effort has been made to normalize and process the information prior to its incorporation to the database. This volume presents the criteria applied to normalize and process the data as well as the soil properties of the various soil types belonging to the provinces of Leon, Zamora and Salamanca of the Comunidad Autonoma de Castilla-Leon. (Author)

  9. MECHANICAL REGENERATION OF SAND WASTE

    Directory of Open Access Journals (Sweden)

    D. I. Gnir

    2005-01-01

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

  10. Oil sands tax expenditures

    International Nuclear Information System (INIS)

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

    2001-01-01

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

  11. Development of a Pediatric Ebola Predictive Score, Sierra Leone1

    Science.gov (United States)

    Wing, Kevin; Naveed, Asad; Gbessay, Musa; Ross, J.C.G.; Checchi, Francesco; Youkee, Daniel; Jalloh, Mohamed Boie; Baion, David E.; Mustapha, Ayeshatu; Jah, Hawanatu; Lako, Sandra; Oza, Shefali; Boufkhed, Sabah; Feury, Reynold; Bielicki, Julia; Williamson, Elizabeth; Gibb, Diana M.; Klein, Nigel; Sahr, Foday; Yeung, Shunmay

    2018-01-01

    We compared children who were positive for Ebola virus disease (EVD) with those who were negative to derive a pediatric EVD predictor (PEP) score. We collected data on all children <13 years of age admitted to 11 Ebola holding units in Sierra Leone during August 2014–March 2015 and performed multivariable logistic regression. Among 1,054 children, 309 (29%) were EVD positive and 697 (66%) EVD negative, with 48 (5%) missing. Contact history, conjunctivitis, and age were the strongest positive predictors for EVD. The PEP score had an area under receiver operating characteristics curve of 0.80. A PEP score of 7/10 was 92% specific and 44% sensitive; 3/10 was 30% specific, 94% sensitive. The PEP score could correctly classify 79%–90% of children and could be used to facilitate triage into risk categories, depending on the sensitivity or specificity required. PMID:29350145

  12. Ebola Virus Disease in Children, Sierra Leone, 2014–2015

    Science.gov (United States)

    Naveed, Asad; Wing, Kevin; Gbessay, Musa; Ross, J.C.G.; Checchi, Francesco; Youkee, Daniel; Jalloh, Mohammed Boie; Baion, David; Mustapha, Ayeshatu; Jah, Hawanatu; Lako, Sandra; Oza, Shefali; Boufkhed, Sabah; Feury, Reynold; Bielicki, Julia A.; Gibb, Diana M.; Klein, Nigel; Sahr, Foday; Yeung, Shunmay

    2016-01-01

    Little is known about potentially modifiable factors in Ebola virus disease in children. We undertook a retrospective cohort study of children <13 years old admitted to 11 Ebola holding units in the Western Area, Sierra Leone, during 2014–2015 to identify factors affecting outcome. Primary outcome was death or discharge after transfer to Ebola treatment centers. All 309 Ebola virus–positive children 2 days–12 years old were included; outcomes were available for 282 (91%). Case-fatality was 57%, and 55% of deaths occurred in Ebola holding units. Blood test results showed hypoglycemia and hepatic/renal dysfunction. Death occurred swiftly (median 3 days after admission) and was associated with younger age and diarrhea. Despite triangulation of information from multiple sources, data availability was limited, and we identified no modifiable factors substantially affecting death. In future Ebola virus disease epidemics, robust, rapid data collection is vital to determine effectiveness of interventions for children. PMID:27649367

  13. Ravenscar Computational Model compliant AADL Simulation on LEON2

    Directory of Open Access Journals (Sweden)

    Roberto Varona-Gómez

    2013-02-01

    Full Text Available AADL has been proposed for designing and analyzing SW and HW architectures for real-time mission-critical embedded systems. Although the Behavioral Annex improves its simulation semantics, AADL is a language for analyzing architectures and not for simulating them. AADS-T is an AADL simulation tool that supports the performance analysis of the AADL specification throughout the refinement process from the initial system architecture until the complete, detailed application and execution platform are developed. In this way, AADS-T enables the verification of the initial timing constraints during the complete design process. In this paper we focus on the compatibility of AADS-T with the Ravenscar Computational Model (RCM as part of the TASTE toolset. Its flexibility enables AADS-T to support different processors. In this work we have focused on performing the simulation on a LEON2 processor.

  14. Leon Trotsky: historiador da Revolução Russa

    OpenAIRE

    Reginaldo Benedito Dias

    2016-01-01

    Este artigo tem o objetivo de analisar a interpretação que Leon Trotsky produziu sobre a Revolução Russa. Abarcando desde o período pré-revolucionário até a fase de liderança de Stalin, as fontes são as obras de Trotsky relacionadas ao tema. Investiga-se a hipótese de que existe uma unidade fundamental na interpretação de Trotsky, assegurada por duas coordenadas. Primeira, o fio condutor da interpretação é a teoria da revolução permanente. Segunda, Outubro de 1917 é o centro de gravidade, na ...

  15. 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.

  16. Windblown Sand Dunes

    Science.gov (United States)

    2003-01-01

    MGS MOC Release No. MOC2-557, 27 November 2003This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows sand dunes and large ripples in a crater in the Hellespontus region of Mars. The winds that formed these dunes generally blew from the left/lower-left (west/southwest). Unlike the majority of dunes on Earth, sand dunes on Mars are mostly made up of dark, rather than light, grains. This scene is located near 50.3oS, 327.5oW. The image covers an area 3 km (1.9 mi) wide, and is illuminated by sunlight from the upper left.

  17. First record of Tenuipalpus uvae De Leon, 1962 (Acari: Tenuipalpidae) in Brazil

    Science.gov (United States)

    This is the first record of Tenuipalpus uvae De Leon (Tenuipalpidae) in Brazil. Specimens were collected from Spondias mombin L. (Anacardiaceae) in the states of Amapa (Northern Brazil) and Pernambuco (northeast)....

  18. “Ah lef ma case fo God”: Faith and agency in Sierra Leone's postwar reconciliation

    NARCIS (Netherlands)

    Millar, G.M.

    2012-01-01

    This article describes a qualitative ethnographic analysis of local experiences of truth-telling performances within Sierra Leone's Truth and Reconciliation Commission. Whereas proponents of truth commissions claim that such processes promote postwar reconciliation, this study found that local

  19. The activity of Leon Idzikovsky firm (book sales, book and music publishing, private public library

    Directory of Open Access Journals (Sweden)

    Hul O.

    2016-01-01

    Full Text Available Leon Idzikovsky firm’s activity has been analyzed and reviewed in this article. The firm was founded by Leon Idzikovsky in 1858 in Kyiv. The author draws attention to the different types of the firm’s activity: bookselling, publishing, private public library etc. The repertoire of the publishing company has been studied in compliance with the firm’s activity periodization. Recreated is the history of Leon Idzikovsky library foundation.The library consisted of nearly 173,000 books, periodicals and sheet music. The author of the article analyzes the thematic structure of the library fonds. Defined is the role of Leon Idzikovsky firm as an important cultural center of prerevolutionary Kyiv

  20. Management of rice seed during insurgency : a case study in Sierra Leone

    NARCIS (Netherlands)

    Mokuwa, G.A.

    2015-01-01

    Keywords: Technography, Oryza glaberrima,  Oryza sativa, farmer hybrids, sub-optimal agriculture, farmer adaptive management, plant genetic resources, peace and extreme (wartime) conditions, local seed channels, selection for robustness, Sierra Leone, West Africa. Abstract

  1. RIVER SAND AND SEA SAND MINING INDUSTRIES IN SRI LANKA

    OpenAIRE

    M. Darshana*1 & S. P. R. Samanthika2

    2017-01-01

    This report has been discussed sea sand and river sand mining in Sri Lanka. To find out the consequences of the present situation regarding sand market and problems arise due to high demand. Currently, Sri lanka is facing sever environmental problems due to sand mining such as river bank erosion, saline water intrusion, destroying of coastal, loss of land and loss of live hood due to flooding. Beside all there are production related problems and marketing problems also can be seen in thi...

  2. Effects of Moisture Content on the Foundry Properties of Yola Natural Sand

    Directory of Open Access Journals (Sweden)

    Paul Aondona IHOM

    2012-08-01

    Full Text Available The effect of moisture content of Yola natural sand has been studied. The moisture content was varied from 1 to 9%. The effect of the moisture content on the green compression strength, green permeability and bulk density was investigated. Particle size distribution of the natural sand, the grain fineness number, average grain size, grain shape and the clay content of the natural sand were also studied. 5% moisture gave the optimum green compression strength of 118.6KN/m2. The dry compression strength increased with moisture content, an optimum value of 4000KN/m2 was obtained at 9% moisture. The Yola natural sand had a grain fineness number of 88.05AFS, average grain size of 335.78 microns and a clay content of 26%. A sand mixture containing 5% moisture was prepared and used to produce a test casting with aluminium scraps, the test casting was sound.

  3. Observation of microstructure of silty sand obtained from gelpush sampler and reconstituted sample

    Directory of Open Access Journals (Sweden)

    Yusa Muhamad

    2017-01-01

    Full Text Available Observation of microstructure study of natural sand i.e. clean sand with fines (particles adjudged to be smaller than 75μm content < 5% (Gel Push A and silty sand with 35% fine content (Gel Push B obtained by gel-push sampling was described. In addition, some observations from reconstituted samples prepared by dry pluviation and moist tamping were presented. Microstructures were investigated statistically by measuring particle orientation. It was evidence that natural sand (either gel push A and B have a preferred orientation i.e. horizontally oriented. Similar particle orientation trend were observed by dry pluviated sample. Undisturbed and dry pluviated samples shows that they are anisotropic in terms of particles orientation. Moist tamped sample on the other hand, results in fairly random orientation with a slight bias towards vertical, thus does not replicate natural sand fabric.

  4. Observation of microstructure of silty sand obtained from gelpush sampler and reconstituted sample

    Science.gov (United States)

    Yusa, Muhamad; Bowman, E. T.; Cubrinovski, Misko

    2017-06-01

    Observation of microstructure study of natural sand i.e. clean sand with fines (particles adjudged to be smaller than 75μm) content particle orientation. It was evidence that natural sand (either gel push A and B) have a preferred orientation i.e. horizontally oriented. Similar particle orientation trend were observed by dry pluviated sample. Undisturbed and dry pluviated samples shows that they are anisotropic in terms of particles orientation. Moist tamped sample on the other hand, results in fairly random orientation with a slight bias towards vertical, thus does not replicate natural sand fabric.

  5. Speleothems and Sand Castles

    Science.gov (United States)

    Hance, Trevor; Befus, Kevin

    2015-01-01

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

  6. Sand Pine Symposium Proceedings

    Science.gov (United States)

    USDA Forest Service Southern Forest Experiment Station

    1973-01-01

    Sand pine, a species well suited to the excessively drained soils common to several million acres in the Southeast, was the subject of this well-attended 3-day meeting. Papers presented included a review of the literature plus results of current research related to this species. Subjects covered ranged from seeds and seedlings to final harvest and conversion...

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

    International Nuclear Information System (INIS)

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

    2002-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Marius Dan Gavriletea

    2017-06-01

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

  9. A biomass energy flow chart for Sierra Leone

    International Nuclear Information System (INIS)

    Amoo-Gottfried, K.; Hall, D.O.

    1999-01-01

    Terrestrial above-ground biomass production and utilisation in Sierra Leone was analysed for the years 1984/5 to 1990/1. The total production of biomass energy was estimated at an annual average of 131 PJ (39% from agriculture, 51% from forestry and 10% from livestock). Of the 117 PJ produced from agricultural and forestry operations, 37 PJ was harvested as firewood and burnt (10.9 GJ or 0.72 t wood per capita per year, supplying 80% of the country's energy), 12 PJ was harvested for food, 66 PJ was unutilised crop and forestry residues, 3 PJ was harvested crop residues for use directly as fuel, and 2 PJ was harvested and used for industrial purposes and not for fuel. Livestock produced wastes with an energy content of 13 PJ of which only 0.1 PJ was collected and used for fuel. Thus 54 PJ (41%) of the 131 PJ of biomass energy produced annually was actually utilised while 49 PJ remained as unused agricultural residues and dung, and a further 27 PJ was unused forestry residues. The total amount of biomass (fuelwood, residues and dung) used directly to provide energy, mostly in households, was estimated at 40 PJ (11.8 GJ per capita per year of 0.79 t fuelwood equivalent). Direct biomass energy utilisation in agroindustry (0.4 PJ) was negligible in comparison. Two assessments of Sierra Leone's biomass standing stock and MAI (mean annual increment) were examined in order to assess the sustainability of various biomass use scenarios. Large differences were found between the MAI of the two assessments, making it difficult to predict sustainability of biomass production and use. The estimation of total standing stock varied between 227 and 366 Mt and the estimation of MAI varied between 15 and 70 Mt. Analysis of the availability and use of the biomass resource is crucial if biomass energy is to be used on a sustainable basis. A software package has been developed and is available to draft biomass flow charts but further work is needed to incorporate social and economic

  10. Influence of Fines Content on the Mechanical Behavior of Methane Hydrate-Bearing Sediments

    Science.gov (United States)

    Hyodo, Masayuki; Wu, Yang; Nakashima, Koji; Kajiyama, Shintaro; Nakata, Yukio

    2017-10-01

    Methane hydrate-bearing sediments with different amounts of fines content and at three densities were artificially prepared under controlled temperature and pressure conditions. The void ratios of specimens after isotropic consolidation tend to decrease with a rise in fines content. The fines particles enter into the pore space between sand grains and densify the specimens. A series of triaxial compression tests were performed to systematically investigate the influences of fines content and density on the shear properties of hydrate-free sediments and methane hydrate-bearing sediments. The test results demonstrate that a rise in fines content within methane hydrate-bearing sediments significantly enhances peak shear strength and promotes dilation behavior. These influences are particularly prominent for specimens at loose packing state. A decrease in void ratio increases the shear strength and stiffness of hydrate-free sediments and methane hydrate-bearing sediments containing fines content of 0% and 8.9%. It is noted that the formation of methane hydrate in samples with varying amounts of fines content increases the stress ratios at the critical state. The addition of fines particles into coarse-grained sand grains alters the internal microstructure of sand matrix and the hydrate formation pattern in the pore space between sand grains and fines particles.

  11. Dark Sand Dunes

    Science.gov (United States)

    2005-01-01

    13 January 2004 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows dark sand dunes in the north polar region of Mars. The dominant winds responsible for these dunes blew from the lower left (southwest). They are located near 76.6oN, 257.2oW. The picture covers an area 3 km (1.9 mi) across; sunlight illuminates the scene from the upper right.

  12. Sand Dune Albedo Feedback

    Directory of Open Access Journals (Sweden)

    Yosef Ashkenazy

    2018-02-01

    Full Text Available Sand dunes cover substantial parts of desert areas. Fully active dunes are bare, while fixed dunes are stabilized by vegetation and biogenic crust, and the dune activity is affected by the wind. Here we suggest the following atmosphere-sand dune feedback: spatial differences in the dunes’ vegetation and biogenic crust cover lead to differences in albedo as the albedo of bare sand is larger than that of vegetation and biogenic crust. This leads to a higher temperature over the vegetated area, resulting in air flow from the bare dune area to the vegetated dune area, thus increasing the wind activity over the vegetated dune area. In turn, this leads to enhanced stress on the vegetation and enhanced dune activity and thus to a decrease in vegetation. These changes in vegetation cover affect the surface albedo, leading to a change in wind activity. We examined this feedback using an atmospheric general circulation model, Weather Research and Forecasting (WRF, in selected regions of the northwestern Negev Desert and the Sahara/Sahel region, and we show that changes in surface albedo do indeed lead to significantly enhanced wind activity over the lower albedo region. We then incorporated this feedback into a simple vegetated dune model, showing that the multiple states associated with active and fixed dunes can be obtained for a larger range of parameters and that the stables states become more extreme (i.e., the fixed dune state becomes more vegetated and the active dune state becomes less vegetated.

  13. Booming Sand Dunes

    Science.gov (United States)

    Vriend, Nathalie

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

  14. Leon Marchlewski: one of the precursors of clinical chemistry.

    Science.gov (United States)

    Ostrowski, Janusz; Muszytowski, Marek; Rutkowski, Bolesław

    2011-01-01

    Dynamic progress in the basic sciences such as clinical chemistry exerted a great influence on the development of clinical science in medicine in the 19th century. We should rate Prof. Leon Marchlewski among the group of prominent foreign and Polish scientists working in that period. Marchlewski was born in 1869 in Wloclawek, Poland. He began his chemical studies in Warsaw and then continued at the Zurich Technical University. After having graduated, he began working in the famous Edward Schunk's laboratory in Kersal near Manchester in England. At that time he achieved recognition for his research on the chemical affinity of dyes of the animal and plant world. Later he cooperated in this field with another great scholar Marceli Nencki. In 1900 he returned to Poland, and in 1906 he took charge of the Department of Medical Chemistry at Jagiellonian University. He was nominated for the Nobel Prize twice in 1913 and 1914 for his numerous achievements in the field of clinical chemistry. He took many positions at Jagiellonian University in Krakow, including dean and rector. In 1930-1935 he was a senator of the Republic of Poland. He died in 1946 in Krakow.

  15. Intestinal parasitic infections and swamp development in Sierra Leone.

    Science.gov (United States)

    Gbakima, Aiah A.

    1994-11-01

    The prevalence of Entamoeba histolytica, Giardia lamblia and other intestinal and urogenital parasites were assessed in five Inland Valley Swamp (IVS) development faming communities in the Moyamba District, South-central Sierra Leone. Stool and urine samples were submitted by 1106 individuals and examined by the iron-haematoxylin staining and the formalin-ether concentration techniques for faecal sample and centrifugation method for the urine samples. The overall parasitic infection rate was 61.7% while 5.9% of the population had multiple infections. E. histolytica infection rate was 12.3 % and most of the infected individuals were passing cysts. Giardia lamblia and Trichomonas vaginalis infection rates were 10.0% and 0.4% respectively. Among the helminth infections, Ascaris lumbricoides was the most commonly observed (13.7%), followed by hookworms (12.1 %), Trichuris trichiura (9.3%), Strongyloides stercoralis (7.7%) and tapeworms (2.6%). The high parasitic infection rate (61.7%) and the frequency of multiple infections indicate an interrelationship of environmental factors which support transmission rather than a single factor.

  16. performance of concrete with partial replacement of fine aggregates

    African Journals Online (AJOL)

    user

    The use of river sand as fine aggregates leads to exploitation of natural resources, lowering of water table, sinking of bridge piers and erosion of river bed [1]. There is a general increase in researches for the use of waste materials in place of natural resources in order to make the concrete industry more sustainable, in terms ...

  17. A Self-Assessment of the Effectiveness to Control Radiation Sources in Sierra Leone

    Energy Technology Data Exchange (ETDEWEB)

    Bun-Tejan, Umaru Remilekun [KAIST, Daejeon (Korea, Republic of); Lee, Byung Soo [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2016-10-15

    There is an urgent need to effectively control sources of ionizing radiation. Sources of ionizing radiation pose serious occupational, public health, and environmental consequences, if not properly controlled. The government of Sierra Leone knows the importance of controlling these sources of ionizing radiation and of establishing an independent Nuclear Safety Infrastructure. Sierra Leone has no nuclear facilities but, it is rapidly developing its infrastructure in order to obtain nuclear technology. However, the regulatory effectiveness in controlling radiation risk is essential for the International Atomic Energy Agency to allow the transfer of nuclear technology. For this reason, this study will evaluate the status of the regulatory authority in Sierra Leone to control radiation risk. The International Atomic Energy Agency (IAEA) review mission to Sierra Leone found that the RPBA did not give sufficient enforcement powers to the Board Secretariat. The research evaluated the status of the regulatory authority of Sierra Leone. The status of the regulatory authority was evaluated against several parameters including management systems, regulatory processes, authorization, inspection, and enforcement. The ability to effectively control ionizing radiation sources depends on the status of the regulatory body. The Integrated Regulatory Review Service Report on Sierra Leone led us to infer that there is a need for the regulatory authority to rapidly improve its ability to control ionizing radiation sources in the country. The findings however, revealed that the overall strengths of the regulatory body in Sierra Leone slightly outnumber the weaknesses. Management systems have a ratio of 0.85:1 of strengths to weaknesses. This ratio makes management systems the weakest parameter evaluated. Thus there is need for stronger collaboration between management staff. The Regulatory processes have a ratio of 1.3:1, authorizations have a ratio of 4.3:1, inspections have ratio of 2

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-11-26

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-11-26

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

  20. Transport and mixing of eolian sand from local sources resulting in variations in grain size in a gypsum dune field, White Sands, New Mexico, USA

    Science.gov (United States)

    Langford, Richard P.; Gill, Thomas E.; Jones, Slade B.

    2016-03-01

    The White Sands Dune Field, New Mexico (USA), provides a unique opportunity to study sources and eolian transport of sand. End member mixing analysis provides unbiased correlation of the grain size distributions of populations that mix sands from four different local source surface types. Textural differences between sources allow local transport paths to be deduced. In total, 1214 surface samples from 10 dunes and 2 downwind-oriented transects were collected. Neither elevation on the dune, lee or stoss location nor distance downwind correlated with mean grain size, coarsest 10% (D90), or sorting. Instead, grain size distributions are controlled by mixing of locally sourced sand populations. Adjacent dunes can have different mean grain sizes, resulting from different local source populations. Local within-dune and between-dune variability resulting from different sand sources dominates any larger-scale trends across and within dunes. Four sand populations are identified, based on microscopically observable differences in grain size, shape and angularity. Each correlates with high loading of a different statistical factor, derived from End Member Mixing Analysis. End Member 1 (EM1) correlates with well-sorted populations of finer-grained, equant, rounded sands. EM2 correlates with samples that contain moderately sorted populations containing angular blades and crystal aggregates associated with erosional interdunes. EM3 is associated with samples of moderately to poorly sorted fine-grained sand containing fine sand-sized gypsum needles collected from areas of vegetated interdunes, and EM4 is associated with moderately well sorted coarse- and very coarse-grained sands collected from granule ripples. These results suggest that downwind mixing of different populations and segregation by different depositional processes influence grain size distributions in the dune field, rather than by dune-scale or erg-scale transport and sorting.

  1. Oil sands development update

    International Nuclear Information System (INIS)

    1999-01-01

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

  2. Defrosting Sand Dunes

    Science.gov (United States)

    2003-01-01

    MGS MOC Release No. MOC2-434, 27 July 2003This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) picture shows retreating patches of frost on a field of large, dark sand dunes in the Noachis region of Mars. Large, windblown ripples of coarse sediment are also seen on some of the dunes. This dune field is located in a crater at 47.5oS, 326.3oW. The scene is illuminated by sunlight from the upper left.

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

    International Nuclear Information System (INIS)

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

    2014-01-01

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

  4. Analysis of Security Sector Reform in Post-Conflict Sierra Leone: A Comparison of Current versus Historical Capabilities

    Science.gov (United States)

    2010-03-01

    article_200513605.shtml (accessed February 14, 2010),;Augustine Samba , "In Sierra Leone, Curfew Order Declared," Awareness Times, October 28, 2009...February 14, 2010). Riley, Jonathon P. The U.K. in Sierra Leone: A Post-Conflict Operation Success? Heritage Foundation, 2006. Samba , Augustine

  5. Sand fly-borne viruses

    OpenAIRE

    Nedvědová Cvanová, Lucie

    2015-01-01

    Sand flies (Diptera: Psychodidae) are important vectors of protozoan, bacterial and viral patogens causing diseases in humans and domestic animals. This thesis summarizes the current knowledge on sand fly-born viruses, their distribution in the World, infection symptoms and life cycle in the nature. These viruses are transmitted by sand flies of genera Phlebotomus, Lutzomyia and Sergentomyia and they can be found on every continent except for Antarctica. They belong into four families, Bunyav...

  6. Effect of Natural Sand Percentages on Fatigue Life of Asphalt Concrete Mixture

    Directory of Open Access Journals (Sweden)

    Nahla Yassub Ahmed

    2016-03-01

    Full Text Available The design of a flexible pavement requires the knowledge of the material properties which are characterized by stiffness and fatigue resistance. The fatigue resistance relates the number of load cycles to failure with the strain level applied to the asphalt mixture. The main objective of this research is the evaluation of the fatigue life of asphalt mixtures by using two types of fine aggregate having different percentages. In this study, two types of fine aggregate were used natural sand (desert sand and crushed sand. The crushed sand was replaced by natural sand (desert sand with different percentages (0%, 25%, 75% and 100% by the weight of the sand (passing sieve No.8 and retained on sieve No.200 and one type of binder (40/50 penetration from Al-Daurah refinery. The samples of beams were tested by four point bending beam fatigue test at the control strain mode (250, 500 and 750 microstrain while the loading frequency (5Hz and testing temperature (20oC according to (AASHTO T321. The experimental work showed that fatigue life (Nf and initial flexural stiffness increased when control strain decreased for asphalt mixtures. Acceptable fatigue life at 750 microstrain was obtained with asphalt concrete mixtures containing 100% crushed sand as well as asphalt concrete contained 25% natural sand. The asphalt concrete contained 100% and 75% of natural sand exhibited high fatigue life at low level of microstrain (250. The main conclusion of this study found that best proportion of natural sand to be added to an asphaltic concrete mixture is falling within the range (0% and 25% by weight of fraction (passing No.8 and retained on No.200 sieve .

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

    Science.gov (United States)

    Frigione, Mariaenrica

    2010-06-01

    An attempt to substitute in concrete the 5% by weight of fine aggregate (natural sand) with an equal weight of PET aggregates manufactured from the waste un-washed PET bottles (WPET), is presented. The WPET particles possessed a granulometry similar to that of the substituted sand. Specimens with different cement content and water/cement ratio were manufactured. Rheological characterization on fresh concrete and mechanical tests at the ages of 28 and 365days were performed on the WPET/concretes as well as on reference concretes containing only natural fine aggregate in order to investigate the influence of the substitution of WPET to the fine aggregate in concrete. It was found that the WPET concretes display similar workability characteristics, compressive strength and splitting tensile strength slightly lower that the reference concrete and a moderately higher ductility. Copyright 2010 Elsevier Ltd. All rights reserved.

  8. Recycling of PET bottles as fine aggregate in concrete

    International Nuclear Information System (INIS)

    Frigione, Mariaenrica

    2010-01-01

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

  9. Overcoming Operational Challenges to Ebola Case Investigation in Sierra Leone.

    Science.gov (United States)

    T Boland, Samuel; Polich, Erin; Connolly, Allison; Hoar, Adam; Sesay, Tom; Tran, Anh-Minh A

    2017-09-27

    The Ebola virus disease (EVD) epidemic that hit West Africa in 2013 was the worst outbreak of EVD in recorded history. While much has been published regarding the international and national-level EVD responses, there is a dearth of literature on district-level coordination and operational structures, successes, and failures. This article seeks to understand how the EVD response unfolded at the district level, namely the challenges to operationalizing EVD surveillance over the course of the outbreak in Port Loko and Kambia districts of Sierra Leone. We present here GOAL Global's understanding of the fundamental challenges to case investigation operations during the EVD response, including environmental and infrastructural, sociocultural, and political and organizational challenges, with insight complemented by a survey of 42 case investigators. Major challenges included deficiencies in transportation and communication resources, low morale and fatigue among case investigators, mismanagement of data, mistrust among communities, and leadership challenges. Without addressing these operational challenges, technical surveillance solutions are difficult to implement and hold limited relevance, due to the poor quality and quantity of data being collected. The low prioritization of operational needs came at a high cost. To mediate this, GOAL addressed these operational challenges by acquiring critical transportation and communication resources to facilitate case investigation, including vehicles, boats, fuel, drivers, phones, and closed user groups; addressing fatigue and low morale by hiring more case investigators, making timely payments, arranging for time off, and providing meals and personal protective equipment; improving data tracking efforts through standard operating procedures, training, and mentorship to build higher-quality case histories and make it easier to access information; strengthening trust in communities by ensuring familiarity and consistency of case

  10. Evaluation of the Leon3 soft-core processor within a Xilinx radiation-hardened field-programmable gate array.

    Energy Technology Data Exchange (ETDEWEB)

    Learn, Mark Walter

    2012-01-01

    The purpose of this document is to summarize the work done to evaluate the performance of the Leon3 soft-core processor in a radiation environment while instantiated in a radiation-hardened static random-access memory based field-programmable gate array. This evaluation will look at the differences between two soft-core processors: the open-source Leon3 core and the fault-tolerant Leon3 core. Radiation testing of these two cores was conducted at the Texas A&M University Cyclotron facility and Lawrence Berkeley National Laboratory. The results of these tests are included within the report along with designs intended to improve the mitigation of the open-source Leon3. The test setup used for evaluating both versions of the Leon3 is also included within this document.

  11. South African Ebola diagnostic response in Sierra Leone: A modular high biosafety field laboratory.

    Science.gov (United States)

    Paweska, Janusz T; Jansen van Vuren, Petrus; Meier, Gunther H; le Roux, Chantel; Conteh, Ousman S; Kemp, Alan; Fourie, Cardia; Naidoo, Prabha; Naicker, Serisha; Ohaebosim, Phumza; Storm, Nadia; Hellferscee, Orienka; Ming Sun, Lisa K; Mogodi, Busisiwe; Prabdial-Sing, Nishi; du Plessis, Desiree; Greyling, Deidre; Loubser, Shayne; Goosen, Mark; McCulloch, Stewart D; Scott, Terence P; Moerdyk, Alexandra; Dlamini, Wesley; Konneh, Kelfala; Kamara, Idrissa L; Sowa, Dauda; Sorie, Samuel; Kargbo, Brima; Madhi, Shabir A

    2017-06-01

    In August 2014, the National Institute for Communicable Diseases (NICD) in South Africa established a modular high-biosafety field Ebola diagnostic laboratory (SA FEDL) near Freetown, Sierra Leone in response to the rapidly increasing number of Ebola virus disease (EVD) cases. The SA FEDL operated in the Western Area of Sierra Leone, which remained a "hotspot" of the EVD epidemic for months. The FEDL was the only diagnostic capacity available to respond to the overwhelming demand for rapid EVD laboratory diagnosis for several weeks in the initial stages of the EVD crisis in the capital of Sierra Leone. Furthermore, the NICD set out to establish local capacity amongst Sierra Leonean nationals in all aspects of the FEDL functions from the outset. This led to the successful hand-over of the FEDL to the Sierra Leone Ministry of Health and Sanitation in March 2015. Between 25 August 2014 and 22 June 2016, the laboratory tested 11,250 specimens mostly from the Western Urban and Western Rural regions of Sierra Leone, of which 2,379 (21.14%) tested positive for Ebola virus RNA. The bio-safety standards and the portability of the SA FEDL, offered a cost-effective and practical alternative for the rapid deployment of a field-operated high biocontainment facility. The SA FEDL teams demonstrated that it is highly beneficial to train the national staff in the course of formidable disease outbreak and accomplished their full integration into all operational and diagnostic aspects of the laboratory. This initiative contributed to the international efforts in bringing the EVD outbreak under control in Sierra Leone, as well as capacitating local African scientists and technologists to respond to diagnostic needs that might be required in future outbreaks of highly contagious pathogens.

  12. The Influences of Iron Ore Tailings as Fine Aggregate on the Strength of Ultra-High Performance Concrete

    Directory of Open Access Journals (Sweden)

    Zhigang Zhu

    2015-01-01

    Full Text Available The present study looks for the feasibility of preparing UHPC with iron ore tailings (IOT for short as fine aggregate. To enhance outstanding high performances, some influences on UHPC mortars were investigated such as different kinds of sands, different mix ratio of sands, and different largest particle size of fine aggregate. The results show that IOT have negligible poorer aggregate performance than silica sands but better than river sands. The strength of UHPC reaches the highest point when silica sands were instead 60% by IOT. As the largest particle size of fine aggregate is decreasing, the strength and frost resistance of UHPC were improved, but the liquidity was decreased. Micropowder of IOT affects the strength and the optimal content was 4%.

  13. Modeling and Optimization of Phenol Formaldehyde Resin Sand Mould System

    Directory of Open Access Journals (Sweden)

    Chate G. R.

    2017-06-01

    Full Text Available Chemical bonded resin sand mould system has high dimensional accuracy, surface finish and sand mould properties compared to green sand mould system. The mould cavity prepared under chemical bonded sand mould system must produce sufficient permeability and hardness to withstand sand drop while pouring molten metal through ladle. The demand for improved values of permeability and mould hardness depends on systematic study and analysis of influencing variables namely grain fineness number, setting time, percent of resin and hardener. Try-error experiment methods and analysis were considered impractical in actual foundry practice due to the associated cost. Experimental matrices of central composite design allow conducting minimum experiments that provide complete insight of the process. Statistical significance of influencing variables and their interaction were determined to control the process. Analysis of variance (ANOVA test was conducted to validate the model statistically. Mathematical equation was derived separately for mould hardness and permeability, which are expressed as a non-linear function of input variables based on the collected experimental input-output data. The developed model prediction accuracy for practical usefulness was tested with 10 random experimental conditions. The decision variables for higher mould hardness and permeability were determined using desirability function approach. The prediction results were found to be consistent with experimental values.

  14. PCE and BNS admixture adsorption in sands with different composition and particle size distribution

    Directory of Open Access Journals (Sweden)

    M. M. Alonso

    2017-02-01

    Full Text Available The choice of a superplasticiser (SP for concrete is of great complexity, as it is well known that properties of the end product are related to admixture and its compatibility with concrete components. Very few studies have been conducted on the compatibility between SPs and the sand of mortars and concretes, however. Practical experience has shown that sand fineness and mineralogical composition affect water demand and admixture consumption. Clay-containing sand has been found also to adsorb SPs, reducing the amount available in solution for adsorption by the cement. This study analysed the isotherms for PCE and BNS superplasticiser adsorption on four sands with different fineness and compositions commonly used to prepare mortars and concretes. BNS-based SP did not adsorb on sands, while PCE-based admixtures exhibited variable adsorption depending on different factors. The adsorption curves obtained revealed that the higher the sand fineness, the finer the particle size distribution and the higher the clay material, the greater was PCE admixture adsorption/ consumption.

  15. PCE and BNS admixture adsorption in sands with different composition and particle size distribution

    International Nuclear Information System (INIS)

    Alonso, M.M.; Martínez-Gaitero, R.; Gismera-Diez, S.; Puertas, F.

    2017-01-01

    The choice of a superplasticiser (SP) for concrete is of great complexity, as it is well known that properties of the end product are related to admixture and its compatibility with concrete components. Very few studies have been conducted on the compatibility between SPs and the sand of mortars and concretes, however. Practical experience has shown that sand fineness and mineralogical composition affect water demand and admixture consumption. Clay-containing sand has been found also to adsorb SPs, reducing the amount available in solution for adsorption by the cement. This study analysed the isotherms for PCE and BNS superplasticiser adsorption on four sands with different fineness and compositions commonly used to prepare mortars and concretes. BNS-based SP did not adsorb on sands, while PCE-based admixtures exhibited variable adsorption depending on different factors. The adsorption curves obtained revealed that the higher the sand fineness, the finer the particle size distribution and the higher the clay material, the greater was PCE admixture adsorption/ consumption. [es

  16. Triaxial tests in Fontainebleau sand

    DEFF Research Database (Denmark)

    Latini, Chiara; Zania, Varvara

    2016-01-01

    The purpose of this internal report is to examine the influence of relative density on the strength and deformation characteristics of Fontainebleau sand. Compression triaxial tests were performed on saturated sand samples with different densities and initial confining pressure. Note...... that the testing procedure and the data processing were carried out according to the specifications of ETCS-F1.97....

  17. Augmenting Sand Simulation Environments through Subdivision and Particle Refinement

    Science.gov (United States)

    Clothier, M.; Bailey, M.

    2012-12-01

    there is a planetary rover interacting with our sand simulation environment. Sand that is actively interacting with a rover wheel will be represented as individual particles whereas sand that is further under the surface will be represented by larger regions of sand. The result of this technique allows for many particles to be represented without the computational complexity. In developing this method, we have further generalized these subdivision regions into any volumetric area suitable for use in the simulation. This is a further improvement of our method as it allows for more compact subdivision sand regions. This helps to fine tune the simulation so that more emphasis can be placed on regions of actively participating sand. We feel that through the generalization of our technique, our research can provide other opportunities within the earth and planetary sciences. Through collaboration with our academic colleagues, we continue to refine our technique and look for other opportunities to utilize our research.

  18. Deep River Velocity and Sediment Profiles and the Suspended Sand Load,

    Science.gov (United States)

    1963-02-01

    be noted from these data that the average vertical velocity profiles of the two streams are practi- cally identical at the respective locations. These...5.03 x IO~~ ATCHAFALAVA RIVER WIDTH : 1587 FT D 5, : 6.75 w 0 ~ FT SIMM ESPORT u : 6.66 FPS WATER TEMP. : 70 F d : 46.3 FT FINE SAND PORTION OP BED...1.34 * 10 3FT SIMM ESPORT ~ : 5.85 FPS WATCR TEMP. :69 ’F d : 47.7 FT FiNE SAND PORTION OP BED MATERIAL : 39.$ ~~ FIG. 16

  19. 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.

  20. Experimental investigation on high performance RC column with manufactured sand and silica fume

    Science.gov (United States)

    Shanmuga Priya, T.

    2017-11-01

    In recent years, the use High Performance Concrete (HPC) has increased in construction industry. The ingredients of HPC depend on the availability and characteristics of suitable alternative materials. Those alternative materials are silica fume and manufactured sand, a by products from ferro silicon and quarry industries respectively. HPC made with silica fume as partial replacement of cement and manufactured sand as replacement of natural sand is considered as sustainable high performance concrete. In this present study the concrete was designed to get target strength of 60 MPa as per guide lines given by ACI 211- 4R (2008). The laboratory study was carried out experimentally to analyse the axial behavior of reinforced cement HPC column of size 100×100×1000mm and square in cross section. 10% of silica fume was preferred over ordinary portland cement. The natural sand was replaced by 0, 20, 40, 60, 80 and 100% with Manufactured Sand (M-Sand). In this investigation, totally 6 column specimens were cast for mixes M1 to M6 and were tested in 1000kN loading frame at 28 days. From this, Load-Mid height deflection curves were drawn and compared. Maximum ultimate load carrying capacity and the least deflection is obtained for the mix prepared by partial replacement of cement with 10% silica fume & natural sand by 100% M-Sand. The fine, amorphous and pozzalonic nature of silica fume and fine mineral particles in M- Sand increased the stiffness of HPC column. The test results revealed that HPC can be produced by using M-Sand with silica fume.

  1. Sand resources, regional geology, and coastal processes for shoreline restoration: case study of Barataria shoreline, Louisiana

    Science.gov (United States)

    Kindinger, Jack G.; Flocks, James G.; Kulp, Mark; Penland, Shea; Britsch, Louis D.

    2002-01-01

    The Louisiana barrier shoreline of Barataria Basin, which lies within the western Mississippi River delta, has undergone significant retreat during the past 100 years. The most practical restoration method to rebuild these shorelines is sand nourishment. Seismic and sonar interpretations verified with geologic samples (vibracores and borings) indicate that there are nine sand targets within the Barataria study area that meet or exceed the minimum criteria for potential resource sites. However, the near surface lithology in the basin is typically silts and clays. Locating suitable sand resources for shoreline restoration is challenging. The sand units are associated with geologic depositional systems such as ebb-tidal deltas, distributary mouth bars, and channel fill (undifferentiated fluvial or tidal inlet channels). The nine potential sand targets consist primarily of fine sand and can be delineated into three surficial and six buried features. The surficial features contain approximately 10% of the total sand resources identified. At least 90% of the sand resources need overburden sediment removed prior to use; almost 570 million yd3 (438.5 mil m3) of overburden will need to be removed if the entire resource is mined. In this study, we identified 396 to 532 mil yd3 (305.8 to 410.8 mil m3) of potential sand deposits for shoreline restoration. Previous studies using less dense survey methods greatly over-estimated sand resources available in this area. Many fluvial channels reported previously as sand-filled are mud-filled. Contrary to these previous studies, few fluvial subsystems in this region have abundant sand resources.

  2. The Violence of Peace and the Role of Education: Insights from Sierra Leone

    Science.gov (United States)

    Novelli, Mario; Higgins, Sean

    2017-01-01

    Research on peacebuilding has mushroomed over the last decade and there is a growing interest in the role of education in supporting peacebuilding processes. This paper engages with these debates, UN peacebuilding activities and the location of education initiatives therein, through a case study of Sierra Leone. In the first part, we explore the…

  3. The Role of Religion During and After the Civil War in Sierra Leone ...

    African Journals Online (AJOL)

    Civil wars in Africa are renowned for their strong religious elements, with religion being used for different purposes and in different capacities. Sierra Leone's civil war (1991-2002), known also as the “rebel war,” had significant religious dimensions. The warring factions used religion for their gain. Beyond that, Muslim and ...

  4. Socio-Ecological Factors Affecting Pregnant Women's Anemia Status in Freetown, Sierra Leone

    Science.gov (United States)

    M'Cormack, Fredanna; Drolet, Judy

    2012-01-01

    Background: Sierra Leone has high maternal mortality. Socio-ecological factors are considered contributing factors to this high mortality. Anemia is considered to be a direct cause of 4% of maternal deaths and an indirect cause of 20-40% of maternal deaths. Purpose: The current study explores socio-ecological contributing factors to the anemia…

  5. Sierra Leone and the Curse of the One-Party State: Contested Ideas ...

    African Journals Online (AJOL)

    However, with the coming of independence that friendship turned quickly into fierce enmity where personal animosities and ambitions turned the political arena into a tense atmosphere characterised by doubts and political crisis. Surprisingly, their enmity was responsible for creating the Sierra Leone version of the one party ...

  6. Looming Over the Nation, Uneasy with the Folks: Locating Mike de Leon in Philippine Cinema

    Directory of Open Access Journals (Sweden)

    Patrick F. Campos

    2006-12-01

    Full Text Available The article draws on filmic, popular, and scholarly references in order to trace how Mike de Leon and his films have been regarded, since his landmark entrance into Philippine cinema as director, up to the present. Specifically, it locates De Leon within the subtly shifting discourse of nationalist film scholarship and historicizing, and discusses how he and his films are written about, identified, associated or networked with other filmmakers and films, or utilized in discourses about the Philippines, Philippine cinema, or Philippine culture.The article locates De Leon as (1 an insider of Philippine cinema history, (2 an outsider of the commercial film industry, and (3 a hero of the mythic Golden Age of the National Cinema. It also maps out his filmography within the nationalist agenda; appraises what filmmakers, commentators, and scholars have articulated about his films; and analyzes the thematic and stylistic trajectories of his later works. Finally, it discusses how De Leon is being written into today’s discourse of Philippine cinema.

  7. "Farming Miners" or "Mining Farmers"?: Diamond Mining and Rural Development in Post-Conflict Sierra Leone

    Science.gov (United States)

    Maconachie, Roy; Binns, Tony

    2007-01-01

    Sierra Leone is currently emerging from a brutal civil war that lasted most of the 1990s, and now has the dubious distinction of being ranked among the world's poorest countries. As thousands of displaced people move back to their villages, a large proportion of the predominantly farm-based rural population are growing food crops for the first…

  8. Child mental health in Sierra Leone : A survey and exploratory qualitative study

    NARCIS (Netherlands)

    Yoder, H.N.C.; Tol, W.A.; Reis, R.; de Jong, J.T.V.M.

    2016-01-01

    Background This study complements the growing amount of research on the psychosocial impact of war on children in Sierra Leone by examining local perceptions of child mental health, formal and informal care systems, help-seeking behaviour and stigma. Methods The study combined: (1) a nationwide

  9. The Great War and Remembrance in Jose Leon Machado's "Memoria das Estrelas sem Brilho"

    Science.gov (United States)

    Azevedo, Milton M.

    2011-01-01

    This article analyzes Jose Leon Machado's novel, "Memoria das Estrelas sem Brilho," as a multilayered historical novel in which a war story provides a background for comments on aspects of early twentieth-century Portuguese society, such as male bonding, religion, sexual mores, and social stratification. (Contains 11 notes.)

  10. Training for Innovation: Capacity-Building in Agricultural Research in Post-War Sierra Leone

    Science.gov (United States)

    Gboku, Matthew L. S.; Bebeley, Jenneh F.

    2016-01-01

    This paper examines how the Sierra Leone Agricultural Research Institute (SLARI) used training and development to build capacity for innovation in agricultural research following the country's civil war which ended in 2002. The Institute's training for innovation addressed different agricultural product value chains (APVCs) within the framework of…

  11. Empowering Women through Education: Evidence from Sierra Leone. NBER Working Paper No. 18016

    Science.gov (United States)

    Mocan, Naci H.; Cannonier, Colin

    2012-01-01

    We use data from Sierra Leone where a substantial education program provided increased access to education for primary-school age children but did not benefit children who were older. We exploit the variation in access to the program generated by date of birth and the variation in resources between various districts of the country. We find that…

  12. Learning Curve Characteristics for Caesarean Section Among Associate Clinicians : A Prospective Study from Sierra Leone

    NARCIS (Netherlands)

    Waalewijn, B.P.; van Duinen, A.; Koroma, A. P.; Rijken, M. J.; Elhassein, M.; Bolkan, H. A.

    2017-01-01

    Background: In response to the high maternal mortality ratio, Sierra Leone has adopted an associate clinician postgraduate surgical task-sharing training programme. Little is known about learning curve characteristics for caesarean sections among associate clinicians. The aim of this study is to

  13. Criminologia, Antropologia e Medicina Legal. Um personagem central: Leonídio Ribeiro

    Directory of Open Access Journals (Sweden)

    Guilherme Gutman

    2010-09-01

    Full Text Available Apresentação da trajetória de Leonídio Ribeiro, em especial a sua abordagem do homossexualismo como representativa das concepções fundantes do campo da criminologia nas primeiras décadas do século XX no Brasil.

  14. Reconstruction versus Transformation: Post-War Education and the Struggle for Gender Equity in Sierra Leone

    Science.gov (United States)

    Maclure, Richard; Denov, Myriam

    2009-01-01

    In post-war contexts, education is widely regarded as essential not only for civic reconciliation, but also as a key force for gender equity. In Sierra Leone, however, despite enhanced educational opportunities for girls, much of the emphasis on post-war educational reconstruction is unlikely to rectify gender inequities that remain entrenched…

  15. Sierra Leone Journal of Biomedical Research - Vol 5, No 1 (2013)

    African Journals Online (AJOL)

    Assessment of the Therapeutic Efficacy of Two Artemisinin-Based Combinations in the Treatment of Uncomplicated Falciparum Malaria among Children Under ... The Use of Mobile Electronic Devices for Public Health Data Collection and Syndromic Surveillance at the Republic Of Sierra Leone Armed Forces · EMAIL FREE ...

  16. Converts to human rights? Popular debate about war and justice in rural central Sierra Leone

    NARCIS (Netherlands)

    Archibald, S.; Richards, P.

    2002-01-01

    Internationally, war in Sierra Leone (1991-2002) is regarded as an instance of violent conflict driven by economic factors (attempts to control the mining of alluvial diamonds). Fieldwork (2000-01) in rural areas recovering from war suggests a very different picture. War victims and combatants from

  17. Scaling up family planning in Sierra Leone: A prospective cost-benefit analysis.

    Science.gov (United States)

    Keen, Sarah; Begum, Hashina; Friedman, Howard S; James, Chris D

    2017-12-01

    Family planning is commonly regarded as a highly cost-effective health intervention with wider social and economic benefits. Yet use of family planning services in Sierra Leone is currently low and 25.0% of married women have an unmet need for contraception. This study aims to estimate the costs and benefits of scaling up family planning in Sierra Leone. Using the OneHealth Tool, two scenarios of scaling up family planning coverage to currently married women in Sierra Leone over 2013-2035 were assessed and compared to a 'no-change' counterfactual. Our costing included direct costs of drugs, supplies and personnel time, programme costs and a share of health facility overhead costs. To monetise the benefits, we projected the cost savings of the government providing five essential social services - primary education, child immunisation, malaria prevention, maternal health services and improved drinking water - in the scale-up scenarios compared to the counterfactual. The total population, estimated at 6.1 million in 2013, is projected to reach 8.3 million by 2035 in the high scenario compared to a counterfactual of 9.6 million. We estimate that by 2035, there will be 1400 fewer maternal deaths and 700 fewer infant deaths in the high scenario compared to the counterfactual. Our modelling suggests that total costs of the family planning programme in Sierra Leone will increase from US$4.2 million in 2013 to US$10.6 million a year by 2035 in the high scenario. For every dollar spent on family planning, Sierra Leone is estimated to save US$2.10 in expenditure on the five selected social sector services over the period. There is a strong investment case for scaling up family planning services in Sierra Leone. The ambitious scale-up scenarios have historical precedent in other sub-Saharan African countries, but the extent to which they will be achieved depends on a commitment from both the government and donors to strengthening Sierra Leone's health system post-Ebola.

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

    NARCIS (Netherlands)

    Van Dijk, T.

    2012-01-01

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

  19. Direct Chlorination of Zircon Sand

    International Nuclear Information System (INIS)

    Dwiretnani Sudjoko; Budi Sulistyo; Pristi Hartati; Sunardjo

    2002-01-01

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

  20. Effect of Binder and Mold parameters on Collapsibility and Surface Finish of Gray Cast Iron No-bake Sand Molds

    Science.gov (United States)

    Srinivasulu Reddy, K.; Venkata Reddy, Vajrala; Mandava, Ravi Kumar

    2017-08-01

    Chemically bonded no-bake molds and cores have good mechanical properties and produce dimensionally accurate castings compared to green sand molds. Poor collapsibility property of CO2 hardened sodium silicate bonded sand mold and phenolic urethane no-bake (PUN) binder system, made the reclamation of the sands more important. In the present work fine silica sand is mixed with phenolic urethane no-bake binder and the sand sets in a very short time within few minutes. In this paper it is focused on optimizing the process parameters of PUN binder based sand castings for better collapsibility and surface finish of gray cast iron using Taguchi design. The findings were successfully verified through experiments.

  1. The Fine Structure Constant

    Indian Academy of Sciences (India)

    IAS Admin

    The article discusses the importance of the fine structure constant in quantum mechanics, along with the brief history of how it emerged. Al- though Sommerfelds idea of elliptical orbits has been replaced by wave mechanics, the fine struc- ture constant he introduced has remained as an important parameter in the field of ...

  2. 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.

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

    Science.gov (United States)

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

    2013-03-01

    The quality of recycled aggregates from construction and demolition waste (CDW) is strictly related to the content of porous and low strength phases, and specifically to the patches of cement that remain attached to the surface of natural aggregates. This phase increases water absorption and compromises the consistency and strength of concrete made from recycled aggregates. Mineral processing has been applied to CDW recycling to remove the patches of adhered cement paste on coarse recycled aggregates. The recycled fine fraction is usually disregarded due to its high content of porous phases despite representing around 50% of the total waste. This paper focus on laboratory mineral separability studies for removing particles with a high content of cement paste from natural fine aggregate particles (quartz/feldspars). The procedure achieved processing of CDW by tertiary impact crushing to produce sand, followed by sieving and density and magnetic separability studies. The attained results confirmed that both methods were effective in reducing cement paste content and producing significant mass recovery (80% for density concentration and 60% for magnetic separation). The production of recycled sand contributes to the sustainability of the construction environment by reducing both the consumption of raw materials and disposal of CDW, particularly in large Brazilian centers with a low quantity of sand and increasing costs of this material due to long transportation distances. Copyright © 2012 Elsevier Ltd. All rights reserved.

  4. The migration of colloidal particles through glacial sand

    International Nuclear Information System (INIS)

    Harrison, I.; Higgo, J.J.W.; Leader, R.; Noy, D.; Smith, B.; Wealthall, G.; Williams, G.M.

    1991-02-01

    Significant concentrations of colloids exist in groundwater and radionuclides may be associated with this colloidal material. This must be taken into consideration in any safety case for a radionuclide waste repository. This report describes column experiments with monodisperse latex beads. A selection of beads with diameters ranging from 0.055 μm to 0.6 μm, some plain and some with carboxyl groups attached, were passed through columns of glacial sand. The breakthrough curves and profiles on the sand columns were studied and will be used to develop and validate colloid migration models. The mobility depended on both size and charge, and the beads appeared to move ahead of a 36Cl tracer until they were trapped. After trapping movement was slow with plain beads appearing to be slightly more mobile than carboxylated beads. The beads were shown to sorb strongly on the fine clay particles in the sand and there was evidence to suggest that they moved with the fines rather than independently. (author)

  5. Simulating Sand Behavior through Terrain Subdivision and Particle Refinement

    Science.gov (United States)

    Clothier, M.

    2013-12-01

    their proximity to the interacting object or force with the sand. To illustrate an example, as a rover wheel moves forward and approaches a particular sand region, that region will continue to subdivide until individual sand particles are represented. Conversely, if the rover wheel moves away, previously subdivided sand regions will recombine. Thus, individual sand particles are available when an interacting force is present but stored away if there is not. As such, this technique allows for many particles to be represented without the computational complexity. We have also further generalized these subdivision regions in our sand framework into any volumetric area suitable for use in the simulation. This allows for more compact subdivision regions and has fine-tuned our framework so that more emphasis can be placed on regions of actively participating sand. We feel that this increases the framework's usefulness across scientific applications and can provide for other research opportunities within the earth and planetary sciences. Through continued collaboration with our academic partners, we continue to build upon our sand simulation framework and look for other opportunities to utilize this research.

  6. The gravel sand transition in a disturbed catchment

    Science.gov (United States)

    Knighton, A. David

    1999-03-01

    More than 40 million cubic metres of mining waste were supplied to the Ringarooma River between 1875 and 1984, leading to successive phases of aggradation and degradation. The natural bed material is gravel but, given the volume of introduced load and the fact that much of the input was less than 5 mm in diameter, the size composition of the bed changed from gravel to sand during the phase of downstream progressive aggradation. A very sharp gravel-sand transition developed in which median grain size decreased from over 30 mm to under 3 mm in less than 500 m. With upstream supplies of mining debris becoming depleted first, degradation followed the same downstream progressive pattern as aggradation, causing the transition to migrate downstream. By 1984, the river could be regarded as a series of zones, each characterized by a particular bed condition: a natural cobble-gravel bed, unaffected by mining inputs (0-32 km); pre-disturbance bed re-exposed by degradation over 35-40 years (32-53 km); sandy substrate with a gravel armour produced by differential transport during degradation (53-65 km); sand dominated but with developing surface patches of coarser material (65-75 km); sandy bed reflecting the size composition of the original mining input (75-118 km). Although the gravel-sand transition itself is sharp, the transitional zone is lengthy (53-75 km). As degradation continues, the gravel-sand transition is expected to progress downstream but it has remained in a stable position for 12 years. Indeed, two major floods during the period released large quantities of sand from the sub-armour layer and newly-formed banks of mine tailings, causing fining both above and below the transition. Surface grain size is an adjustable component in the transitional zone as the river strives to recover from a major anthropogenic disturbance.

  7. Faunistic assemblages of a sublittoral coarse sand habitat of the northwestern Mediterranean

    Directory of Open Access Journals (Sweden)

    Eva Pubill

    2011-02-01

    Full Text Available The sublittoral megabenthic assemblages of a northwestern Mediterranean coarse sandy beach exploited for the bivalve Callista chione were studied. The spatial and bathymetric variability of its distinctive faunal assemblages was characterised by quantitative sampling performed with a clam dredge. The taxa studied were Mollusca Bivalvia and Gastropoda, Crustacea Decapoda, Echinodermata and Pisces, which accounted for over 99% of the total biomass. Three well-differentiated species assemblages were identified: (1 assemblage MSS (Medium Sand Shallow in medium sand (D50=0.37 mm and shallow waters (mean depth =6.5 m, (2 assemblage CSS (Coarse Sand Shallow in coarse sand (D50=0.62 mm in shallow waters (mean depth =6.7 m, and (3 assemblage CSD (Coarse Sand Deep in coarse sand (D50=0.64 mm in deeper waters (mean depth =16.2 m. Assemblage MSS was characterised by the codominance of the bivalves Mactra stultorum and Acanthocardia tuberculata. C. chione was dominant in both density and biomass in assemblages CSS and CSD. The occurrence of the crab Thia scutellata also characterised assemblage CSS, whereas the occurrence of the sea urchin Echinocardium mediterraneum characterised assemblage CSD. A depth breaking point of around 10 m determined the discontinuity between assemblages CSS and CSD, which was related to the closure depth of the beaches in the study area. Species richness was highest in the coarse sand communities; however, Shannon-Wiener diversity and Pielou equitability indexes were higher in the shallow fine sand community.

  8. Modeling the effects of pulsed versus chronic sand inputs on salmonid spawning habitat in a low-gradient gravel-bed river

    Science.gov (United States)

    Oscar Maturana; Daniele Tonina; James A. McKean; John M. Buffington; Charles H. Luce; Diego Caamano

    2013-01-01

    It is widely recognized that high supplies of fine sediment, largely sand, can negatively impact the aquatic habitat quality of gravel-bed rivers, but effects of the style of input (chronic vs. pulsed) have not been examined quantitatively. We hypothesize that a continuous (i.e. chronic) supply of sand will be more detrimental to the quality of aquatic habitat than an...

  9. Quality improvement in emergency service delivery: Assessment of knowledge and skills amongst emergency nurses at Connaught Hospital, Sierra Leone

    Directory of Open Access Journals (Sweden)

    Hedda Bøe Nyhus

    2017-09-01

    Conclusion: This study has identified key aspects of emergency nursing speciality training to be developed through theoretical and skill-based education provided by the nursing schools and hospital clinical facilities in Sierra Leone.

  10. Nobel Prize winning physicist to speak at Rensselaer Nov. 20 Leon Lederman to discuss pre college science education

    CERN Multimedia

    2002-01-01

    Leon Lederman, Nobel Prize-winner, will offer some radical ideas for improving pre-college science education when he delivers the annual Robert Resnick Lecture at Rensselaer Polytechnic Institute's Russell Sage Laboratory (1/2 page).

  11. Annual report of the Basque-Leon colliery company. Sociedad Anonima Hullera Vasco-Leonesa. Memoria 1987

    Energy Technology Data Exchange (ETDEWEB)

    1988-01-01

    Annual report on the activities of the Basque-Leon Colliery Company for 1987 including: production trends and economic parameters, employment and safety, new mines, reserves, investments, financial status, economic assessment. 24 figs., 30 tabs.

  12. Sand in the salt marsh : Contribution of high-energy conditions to salt-marsh accretion

    NARCIS (Netherlands)

    de Groot, Alma V.; Veeneklaas, Roos M.; Bakker, Jan P.

    2011-01-01

    The environmental dynamics at barrier-island salt marshes are reflected in lateral and vertical textural patterns of the marsh sediment. During normal conditions, fine-grained sediment is deposited, whereas during high-energy conditions also sand accretion can occur. This paper describes the

  13. Sand in the salt marsh: Contribution of high-energy conditions to salt-marsh accretion

    NARCIS (Netherlands)

    Groot, de A.V.; Veeneklaas, R.M.; Bakker, J.P.

    2011-01-01

    The environmental dynamics at barrier-island salt marshes are reflected in lateral and vertical textural patterns of the marsh sediment. During normal conditions, fine-grained sediment is deposited, whereas during high-energy conditions also sand accretion can occur. This paper describes the

  14. Intertidal benthic community ecology of sand-dwelling macroinvertebrates of Goa beaches

    Digital Repository Service at National Institute of Oceanography (India)

    Harkantra, S.N.; Parulekar, A.H.

    , is relatively unstable, less productive, and supports a poor benthic fauna. In contrast, an estuarine beach at Siridao, having fine sand-grain size, is comparatively stable, more productive, and exhibits a rich fauna. This indicates the richness of benthic life...

  15. The Effect of Soil Particle Arrangement on Shear Strength Behavior of Silty Sand

    Directory of Open Access Journals (Sweden)

    Nik Norsyahariati Nik Daud

    2016-01-01

    Full Text Available The presence of fines in sandy soil is recognized as a problem in geotechnical engineering. It is often assumed that the strength and liquefaction potential of a soil decreases with increasing fines content. Sand with a significant amount of fines is always encountered in geotechnical engineering projects. The main interest of this paper is to study the effect of particles arrangement and stress behaviour on sand and silty sand sample. The objectives are to determine the basic properties as well as the morphological and mineralogical properties and the relationship of those properties to the stress behaviour of the soils. Sand-silt mixtures with fines contents of 20% and 40% were prepared and a series of testing was carried out to determine their basic properties, morphological and thin section properties, and mechanical properties by using direct shear box equipment. Results show that the basic properties and morphological properties of soil affect the mechanical behaviour of soil. Shape of the soil particle can influence the packing of the soil, hence altering the mechanical behaviour of the soil. From the thin section, the soil is observed to be well graded and have a dense packing while the minerals observed were mainly quartz and rutile.

  16. Predicting the abundance of clays and quartz in oil sands using hyperspectral measurements

    Science.gov (United States)

    Entezari, Iman; Rivard, Benoit; Geramian, Mirjavad; Lipsett, Michael G.

    2017-07-01

    Clay minerals play a crucial role in the processability of oil sands ores and in the management of tailings. An increase in fine content generally leads to a decrease in both bitumen recovery performance and tailings settling rate. It is thus important to identify clay types and their abundance in oil sands ores and tailings. This study made use of oil sands samples characterized for quantitative mineralogy by x-ray diffraction, to gain an understanding of changes in the reflectance spectra of oil sands. The sample suite included bitumen-removed oil sands ore samples and their different fine size fractions. Spectral metrics applicable to the prediction of quartz and clay contents in oil sands were then derived with a focus on metrics correlating with sample content in total 2:1 clays (total of illite and illite-smectite) and kaolinite. Metrics in the shortwave infrared (SWIR) and longwave infrared (LWIR) were found to correlate with mineral contents. The best predictions of clays and quartz were achieved using LWIR metrics (R2 > 0.89). Results also demonstrated the applicability of LWIR metrics in the prediction of kaolinite and total 2:1 clays.

  17. Estudio de enriquecimiento nutricional de dos especies de Leones marinos (Otaria flavescens y Zalophus californianus) en Aquanatura (Benidorm)

    OpenAIRE

    Llorens García, Inés

    2016-01-01

    El enriquecimiento ambiental es un método de reducir el estrés y los comportamientos inadecuados de animales en cautiverio, ayudando a su vez a aumentar el bienestar de estos. En este trabajo se pretende realizar un estudio de enriquecimiento nutricional de dos leones marinos de California (Zalophus Californianus) y dos leones marinos de la Patagonia (Otaria flavescens). Así, se ha estudiado el comportamiento de los cuatro individuos sobre un dispensador de alimento nuevo para ellos, midiendo...

  18. Mycorrhizal inoculum potentials of pure reclamation materials and revegetated tailing sands from the Canadian oil sand industry.

    Science.gov (United States)

    Bois, G; Piché, Y; Fung, M Y P; Khasa, D P

    2005-05-01

    Recent improvements in the management of oil sand tailings used by the Canadian oil sand industry have resulted in the production of composite tailing sands (CT): a new challenging material for reclamation work. Jack pine (Pinus banksiana Lamb.), hybrid poplar (Populus deltoides Bartr. ex Marsh. xPopulus nigra L.) and red clover (Trifolium pratense L.) plants were used in an 8-week greenhouse bioassay to evaluate the mycorrhizal inoculum potential of CT. This inoculum potential was compared with that of three other reclamation materials [common tailing sands (TS), deep overburden (OB) and muskeg peat (MK)], and with three sites reclaimed in 1982 (R82), 1988 (R88) and 1999 (R99). CT was devoid of active mycorrhizal propagules while all other materials showed some level of inoculum potential. Arbuscular mycorrhizal fungi were observed on roots of clover or poplar grown in TS, OB, and all substrates containing peat (MK, R82, R88 and R99). Pine roots were also colonized by vesicle-forming hyphae of an unidentified fine endophyte and by dark septate fungi. Ectomycorrhizas (ECM) were observed on pine and poplar grown in OB, MK, and in soils from the two older reclaimed sites (R82 and R88). Using morpho- and molecular typing, six ECM fungi were identified to the genus or species level: Laccaria sp., Thelephora americana, Wilcoxina sp. (E-strain), Tuber sp. (I-type), a Sebacinoid, and a Pezizales species. Laccaria sp. and Wilcoxina sp. were the most frequently observed ECM species.

  19. Effect of Sand Base Grade and Density of Moulding Sands with Sodium Silicate on Effectiveness of Absorbing Microwaves

    Directory of Open Access Journals (Sweden)

    Stachowicz M.

    2016-09-01

    Full Text Available In the paper, presented is a research on effectiveness of absorbing electromagnetic waves at frequency 2.45 GHz by unhardened moulding sands prepared of three kinds of high-silica base and a selected grade of sodium silicate. Measurements of power loss of microwave radiation (Pin expressed by a total of absorbed power (Pabs, output power (Pout and reflected power (Pref were carried-out on a stand of semiautomatic microwave slot line. Values of microwave power loss in the rectangular waveguide filled with unhardened moulding sands served for determining effectiveness of microwave heating. Balance of microwave power loss is of technological and economical importance for manufacture of high-quality casting moulds and cores of various shapes and sizes. It was found that relative density influences parameters of power output and power reflected from samples of moulding sand placed in a waveguide. Absorption expressed by the parameter Pabs is not related to granularity of high-silica base: fine, medium and coarse. It was found that the semiautomatic microwave slot line supports evaluation of effectiveness of microwave absorption on the grounds of power loss measurements and enables statistic description of influence of relative density of the sandmix on penetration of electromagnetic waves in unhardened moulding sands.

  20. Landsat-Derived Estimates of Mangrove Extents in the Sierra Leone Coastal Landscape Complex during 1990-2016.

    Science.gov (United States)

    Mondal, Pinki; Trzaska, Sylwia; de Sherbinin, Alex

    2017-12-21

    This study provides the first assessment of decadal changes in mangrove extents in Sierra Leone. While significant advances have been made in mangrove mapping using remote sensing, no study has documented long-term changes in mangrove extents in Sierra Leone-one of the most vulnerable countries in West Africa. Such understanding is critical for devising regional management strategies that can support local livelihoods. We utilize multi-date Landsat data and cloud computational techniques to quantify spatiotemporal changes in land cover, with focus on mangrove ecosystems, for 1990-2016 along the coast of Sierra Leone. We specifically focus on four estuaries-Scarcies, Sierra Leone, Yawri Bay, and Sherbro. We relied on the k-means approach for an unsupervised classification, and validated the classified map from 2016 using ground truth data collected from Sentinel-2 and high-resolution images and during field research (accuracy: 95%). Our findings indicate that the Scarcies river estuary witnessed the greatest mangrove loss since 1990 (45%), while the Sierra Leone river estuary experienced mangrove gain over the last 26 years (22%). Overall, the Sierra Leone coast lost 25% of its mangroves between 1990 and 2016, with the lowest coverage in 2000, during the period of civil war (1991-2002). However, natural mangrove dynamics, as supported by field observations, indicate the potential for regeneration and sustainability under carefully constructed management strategies.

  1. Fine Arts Database (FAD)

    Data.gov (United States)

    General Services Administration — The Fine Arts Database records information on federally owned art in the control of the GSA; this includes the location, current condition and information on artists.

  2. Analyses of fine paste ceramics

    International Nuclear Information System (INIS)

    Sabloff, J.A.

    1980-01-01

    Four chapters are included: history of Brookhaven fine paste ceramics project, chemical and mathematical procedures employed in Mayan fine paste ceramics project, and compositional and archaeological perspectives on the Mayan fine paste ceramics

  3. Analyses of fine paste ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Sabloff, J A [ed.

    1980-01-01

    Four chapters are included: history of Brookhaven fine paste ceramics project, chemical and mathematical procedures employed in Mayan fine paste ceramics project, and compositional and archaeological perspectives on the Mayan fine paste ceramics. (DLC)

  4. Properties of palm oil fuel ash cement sand brick containing pulverized cockle shell as partial sand replacement

    Science.gov (United States)

    Mat Aris, S.; Muthusamy, K.; Uzer, A.; Ahmad, S. Wan

    2018-04-01

    Environmental pollution caused by the disposal of solid wastes generated from both palm oil industry and cockle shell trade has motivated researches to explore the potential of these wastes. Integrating these wastes in production of construction material is one of the ways to reduce amount of waste thrown at dumping area. Thus, the present investigation investigates the performance of palm oil fuel ash (POFA) cement sand brick containing pulverized cockle shell as partial fine aggregate replacement. All mixes used contain 20% of POFA as partial cement replacement. Total of six mixes were prepared by adding a range of pulverized cockle shell that is 0%, 10%, 20%, 30%, 40% and 50% as partial sand replacement. The mixes were prepared in form of brick. All the water cured samples were tested for compressive strength and flexural strength until 28 days. Findings show that brick produced using 20% pulverized cockle shell exhibit the highest compressive strength and flexural strength also the lowest water absorption value.

  5. Chemical control trials against Phytophthora capsici (Leon on pepper cultivations in Morocco

    Directory of Open Access Journals (Sweden)

    Pussemier, L.

    1988-01-01

    Full Text Available Chemical control trials against Phytophthora capsici (Leon on pepper cultivations in Morocco. Pepper protection trials against collar and root rot have been undertaken under laboratory and culture conditions using Aliette (80 % of phosethylaluminium and Ridomil M 58 (10 % of metalaxyl associated to 48 % of maneb. It has been proved that, contrary to Ridomil M 58, Aliette does not protect the hostplant when the Phytophthora capsici (Leon zoospores are used as inoculum. But both fongicides are active when inoculating with a mycelian suspension. Trials undertaken under plastic glasshouses confirmed the laboratory results both with an artificial inoculation and with a natural one on contaminated soil. Only Ridomil M 58 provides satisfactory protection during the first weeks after the treatment. When disease propagation conditions are particularly favorable (permanent presence of an active inoculum source, the protection given by repeated Ridomil M 58 applications gradually disappears after a few weeks.

  6. The gospel in context: Hiebert’s critical contextualisation and charismatic movements in Sierra Leone

    Directory of Open Access Journals (Sweden)

    Joseph B. Bangura

    2016-09-01

    Full Text Available This article examines the process of contextualisation adopted by charismatic movements (CMs in Sierra Leone. In it I use Hiebert’s model of critical contextualisation to evaluate the biblical depth and cultural sensitivity of the CMs’ contextualisation. Three ongoing cultural issues are especially highlighted as crucial and are used as the point of departure in the discussions: initiation ceremonies, polygamous marriage practices and ancestral rituals. The article concludes that, whilst the danger of syncretism is likely to occur where uncritical forms of contextualisation are employed, the CMs in Sierra Leone are attempting to address themes that are concurrent with the African sensibilities of its followers. This is an effort to build authentic forms of Christianity that are faithful to Holy Scripture and relevant to the setting in which they are developed.

  7. Solvent extraction of oil-sand components for determination of trace elements by neutron activation analysis

    International Nuclear Information System (INIS)

    Jacobs, F.S.; Filby, R.H.

    1983-01-01

    Instrumental neutron activation analysis was used to measure the concentrations of 30 elements in Athabasca oil sands and oil-sand components. The oil sands were separated into solid residue, bitumen, and fines by Soxhlet extraction with toluene-bitumen extract. The mineral content of the extracted bitumen was dependent on the treatment of the oil sand prior to extraction. The geochemically important and organically associated trace element contents of the bitumen (and asphaltenes) were determined by subtracting the mineral contributions from the total measured concentrations. The method allows analysis of the bitumen without the necessity of ultracentrifugation or membrane filtration, which might remove geochemically important components of the bitumen. The method permits classification of trace elements into organic and inorganic combinations

  8. Study on Compressive Strength of Quarry Dust as Fine Aggregate in Concrete

    OpenAIRE

    Shyam Prakash, K.; Rao, Ch. Hanumantha

    2016-01-01

    The concept of replacement of natural fine aggregate by quarry dust which is highlighted in the study could boost the consumption of quarry dust generated from quarries. By replacement of quarry dust, the requirement of land fill area can be reduced and can also solve the problem of natural sand scarcity. The availability of sand at low cost as a fine aggregate in concrete is not suitable and that is the reason to search for an alternative material. Quarry dust satisfies the reason behind the...

  9. [Fine root dynamics and its relationship with soil fertility in tropical rainforests of Chocó].

    Science.gov (United States)

    Quinto, Harley; Caicedo, Haylin; Thelis Perez, May; Moreno, Flavio

    2016-12-01

    The fine roots play an important role in the acquisition of water and minerals from the soil, the global carbon balance and mitigation of climate change. The dynamics (productivity and turnover) of fine roots is essential for nutrient cycling and carbon balance of forest ecosystems. The availability of soil water and nutrients has significantly determined the productivity and turnover of fine roots. It has been hypothesized that fine roots dynamics increases with the availability of soil resources in tropical forest ecosystems. To test this hypothesis in tropical rainforests of Chocó (ecosystems with the highest rainfall in the world), five one-ha permanent plots were established in the localities of Opogodó and Pacurita, where the productivity and turnover of fine roots were measured at 0-10 cm and 10-20 cm depth. The measurement of the fine root production was realized by the Ingrowth core method. The fine root turnover was measured like fine roots production divided mean annual biomass. In addition, soil fertility parameters (pH, nutrients, and texture) were measured and their association with productivity and turnover of fine roots was evaluated. It was found that the sites had nutrient-poor soils. The localities also differ in soil; Opogodó has sandy soils and flat topography, and Pacurita has clay soils, rich in aluminum and mountainous topography. In Opogodó fine root production was 6.50 ± 2.62 t/ha.yr (mean ± SD). In Pacurita, fine root production was 3.61 ± 0.88 t/ha.yr. Also in Opogodó, the fine root turnover was higher than in Pacurita (1.17 /y and 0.62 /y, respectively). Fine root turnover and production in the upper soil layers (10 cm upper soil) was considerably higher. Productivity and turnover of fine roots showed positive correlation with pH and contents of organic matter, total N, K, Mg, and sand; whereas correlations were negative with ECEC and contents of Al, silt, and clay. The percentage of sand was the parameter that best explained

  10. Access to health care, reproductive health and disability: a large scale survey in Sierra Leone.

    Science.gov (United States)

    Trani, Jean-Francois; Browne, Joyce; Kett, Maria; Bah, Osman; Morlai, Teddy; Bailey, Nicki; Groce, Nora

    2011-11-01

    This is the first study to compare health status and access to health care services between disabled and non-disabled men and women in urban and peri-urban areas of Sierra Leone. It pays particular attention to access to reproductive health care services and maternal health care for disabled women. A cross-sectional study was conducted in 2009 in 5 districts of Sierra Leone, randomly selecting 17 clusters for a total sample of 425 households. All adults who were identified as being disabled, as well as a control group of randomly selected non-disabled adults, were interviewed about health and reproductive health. As expected, we showed that people with severe disabilities had less access to public health care services than non-disabled people after adjustment for other socioeconomic characteristics (bivariate modelling). However, there were no significant differences in reporting use of contraception between disabled and non-disabled people; contrary to expectations, women with disabilities were as likely to report access to maternal health care services as did non-disabled women. Rather than disability, it is socioeconomic inequality that governs access to such services. We also found that disabled women were as likely as non-disabled women to report having children and to desiring another child: they are not only sexually active, but also need access to reproductive health services. We conclude that disparity in access to government-supported health care facilities constitutes a major and persisting health inequity between persons with and without disabilities in Sierra Leone. Ensuring equal access will require further strengthening of the country's health care system. Furthermore, because the morbidity and mortality rates of pregnant women are persistently high in Sierra Leone, assessing the quality of services received is an important priority for future research. Copyright © 2011 Elsevier Ltd. All rights reserved.

  11. Comercio y marketing elextronico de los productos agroalimentarios de calidad certificada en Castilla y Leon

    OpenAIRE

    Kallas, Zein; Gomez-Limon Rodriguez, Jose A.; Martin Fernandez, Roberto San

    2005-01-01

    El Comercio Electronico de los productos agroalimentaros aun posee un volumen minimo comparado con otros sectores. No obstante, es previsible un importante desarrollo en un futuro proximo, especialmente en relacion a los productos de mayor calidad. Este trabajo pretende analizar la situacion actual del Comercio y Marketing Electronico de productors agroalimentarios de calidad certificada en Castilla y Leon, asi como estudiar las posibilidades de desarrollo en un futuro proximo. Para lograrlo ...

  12. MODE OF PRODUCTION ANS EDUCATION: QUESTIONS ON THE MODE OF LIFE: A CONTRIBUTION OF LEON TROTSKY

    Directory of Open Access Journals (Sweden)

    Celi Zulke Taffarel

    2009-06-01

    Full Text Available The text addresses the importance of consideration of the contribution of Leon Trotsky - when you look at the issue of mode of life resulting from the general production of existence - to think clearly articulate an educational proposal for the construction of socialist history project. The need to think the human based on the question of cultural activists, on the fight for a policy of cultural formation.

  13. Distance, accessibility and costs. Decision-making during childbirth in rural Sierra Leone: A qualitative study.

    Directory of Open Access Journals (Sweden)

    Laura Treacy

    Full Text Available Sierra Leone has one of the highest maternal mortality ratios in the world. Efforts to reduce maternal mortality have included initiatives to encourage more women to deliver at health facilities. Despite the introduction of the free health care initiative for pregnant women, many women still continue to deliver at home, with few having access to a skilled birth attendant. In addition, inequalities between rural and urban areas in accessing and utilising health facilities persist. Further insight into how and why women make decisions around childbirth will help guide future plans and initiatives in improving maternal health in Sierra Leone. The objective of this study was to explore the perceptions and decision-making processes of women and their communities during childbirth in rural Sierra Leone.Data were collected through seven focus group discussions and 22 in-depth interviews with recently pregnant women and their community members in two rural villages. Data were analysed using systematic text condensation. Findings revealed that decision-making processes during childbirth are dynamic, intricate and need to be understood within the broader social context that they take place. Factors such as distance and lack of transport, perceived negative behaviour of hospital staff, direct and indirect financial obstacles, as well as the position of women in society all interact and influence how and what decisions are made.Pregnant women face multiple interacting vulnerabilities that influence their healthcare-seeking decisions during pregnancy and childbirth. Future initiatives to improve access and utilisation of safe healthcare services for pregnant women need to be based on adequate knowledge of structural constraints and health inequities that affect women in rural Sierra Leone.

  14. The University of Guanajuato Institute of Physics (IFUG). Leon Lederman, the big boss

    Science.gov (United States)

    Félix, J.; Moreno, G.

    2000-08-01

    This paper is to honor Leon Lederman trajectory in experimental high energy physics and, in particular and most, his invaluable help to start experimental high energy physics in Mexico and in Latin America in general. That began around 1982. Now, in 1999, there are many active groups in Latin America that devote their best efforts to experimental high energy physics. In Mexico there are six groups. .

  15. Natural law Judaism? The genesis of bioethics in Hans Jonas, Leo Strauss, and Leon Kass.

    Science.gov (United States)

    Vogel, Lawrence

    2006-01-01

    Leon Kass is much misunderstood. He is not simply a Republican ideologue who tailored his ideas to break out of the ivory tower and into the halls of power. Nor does he look simply to use human nature as a moral guide. When the full range of his writings is considered and set in the tradition of his teachers, Hans Jonas and Leo Strauss, what emerges is a natural law position colored by religious revelation.

  16. Complementary description of Neoseiulus tunus (De Leon) (Acari: Mesostigmata: Phytoseiidae) and observation on its reproductive strategy

    OpenAIRE

    Cavalcante, Ana C.C.; Demite, Peterson R; Amaral, Felipe S.R.; Lofego, Antonio C.; de Moraes, Gilberto J.

    2017-01-01

    International audience; Neoseiulus tunus (De Leon) is one of the most frequent species of this genus in the Neotropical Region, reported on several plants and localities. In this study, the morphological characterization of various Brazilian populations of this species is presented. Females and males are illustrated. Neoseiulus neotunus (Denmark & Muma) is here considered a junior synonymn of N. tunus. Thelytokous parthenogenesis is reported for the first time for this species, based on two p...

  17. Sedimentary controls on modern sand grain coat formation

    Science.gov (United States)

    Dowey, Patrick J.; Worden, Richard H.; Utley, James; Hodgson, David M.

    2017-05-01

    Coated sand grains can influence reservoir quality evolution during sandstone diagenesis. Porosity can be reduced and fluid flow restricted where grain coats encroach into pore space. Conversely pore-lining grain coats can restrict the growth of pore-filling quartz cement in deeply buried sandstones, and thus can result in unusually high porosity in deeply buried sandstones. Being able to predict the distribution of coated sand grains within petroleum reservoirs is thus important to help find good reservoir quality. Here we report a modern analogue study of 12 sediment cores from the Anllóns Estuary, Galicia, NW Spain, collected from a range of sub-environments, to help develop an understanding of the occurrence and distribution of coated grains. The cores were described for grain size, bioturbation and sedimentary structures, and then sub-sampled for electron and light microscopy, laser granulometry, and X-ray diffraction analysis. The Anllóns Estuary is sand-dominated with intertidal sand flats and saltmarsh environments at the margins; there is a shallowing/fining-upwards trend in the estuary-fill succession. Grain coats are present in nearly every sample analysed; they are between 1 μm and 100 μm thick and typically lack internal organisation. The extent of grain coat coverage can exceed 25% in some samples with coverage highest in the top 20 cm of cores. Samples from muddy intertidal flat and the muddy saltmarsh environments, close to the margins of the estuary, have the highest coat coverage (mean coat coverage of 20.2% and 21.3%, respectively). The lowest mean coat coverage occurs in the sandy saltmarsh (10.4%), beyond the upper tidal limit and sandy intertidal flat environments (8.4%), close to the main estuary channel. Mean coat coverage correlates with the concentration of clay fraction. The primary controls on the distribution of fine-grained sediment, and therefore grain coat distribution, are primary sediment transport and deposition processes that

  18. Experiences of providing prosthetic and orthotic services in Sierra Leone--the local staff's perspective.

    Science.gov (United States)

    Magnusson, Lina; Ahlström, Gerd

    2012-01-01

    In Sierra Leone, West Africa, there are many people with disabilities in need of rehabilitation services after a long civil war. The aim of this qualitative study was to explore the experiences of prosthetic and orthotic service delivery in Sierra Leone from the local staff's perspective. Fifteen prosthetic and orthotic technicians working at all the rehabilitation centres providing prosthetic and orthotic services in Sierra Leone were interviewed. The interviews were transcribed and subjected to latent content analysis. One main theme emerged: sense of inability to deliver high-quality prosthetic and orthotic services. This main theme was generated from eight sub-themes: Desire for professional development; appraisals of work satisfaction and norms; patients neglected by family; limited access to the prosthetic and orthotic services available; problems with materials and machines; low public awareness concerning disabilities; marginalisation in society and low priority on the part of government. The findings illustrated traditional beliefs about the causes of disability and that the public's attitude needs to change to include and value people with disabilities. Support from international organisations was considered necessary as well as educating more prosthetic and orthotic staff to a higher level.

  19. Mental health care during the Ebola virus disease outbreak in Sierra Leone.

    Science.gov (United States)

    Kamara, Stania; Walder, Anna; Duncan, Jennifer; Kabbedijk, Antoinet; Hughes, Peter; Muana, Andrew

    2017-12-01

    Reported levels of mental health and psychosocial problems rose during the 2014-2015 Ebola virus disease outbreak in Sierra Leone. As part of the emergency response, existing plans to create mental health units within the existing hospital framework were brought forward. A nurse-led mental health and psychosocial support service, with an inpatient liaison service and an outpatient clinic, was set up at the largest government hospital in the country. One mental health nurse trained general nurses in psychological first aid, case identification and referral pathways. Health-care staff attended mental well-being workshops on coping with stigma and stress. Mental health service provision in Sierra Leone is poor, with one specialist psychiatric hospital to serve the population of 7 million. From March 2015 to February 2016, 143 patients were seen at the clinic; 20 had survived or had relatives affected by Ebola virus disease. Half the patients (71) had mild distress or depression, anxiety disorders and grief or social problems, while 30 patients presented with psychosis requiring medication. Fourteen non-specialist nurses received mental health awareness training. Over 100 physicians, nurses and auxiliary staff participated in well-being workshops. A nurse-led approach within a non-specialist setting was a successful model for delivering mental health and psychosocial support services during the Ebola outbreak in Sierra Leone. Strong leadership and partnerships were essential for establishing a successful service. Lack of affordable psychotropic medications, limited human resources and weak social welfare structures remain challenges.

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

    CSIR Research Space (South Africa)

    Ojuri, OO

    2017-01-01

    Full Text Available The characterization of the Nigerian Igbokoda Standard Sand was performed by X-ray diffraction, IR and Raman Spectroscopy, and nuclear magnetic resonance techniques. The principal reflections occurring at the d-Spacings of 4.25745, 3.34359, 2...

  1. Study on strength characteristics of concrete using M-Sand and coconut fibers

    Science.gov (United States)

    Neeraja, D.; Wani, Amir Iqbal; Kamili, Zainulabideen; Agarwal, Krishnakant

    2017-11-01

    In the current world, concrete has become a very important part of the construction industry and the materials which are used in making concrete have evolved due to better quality of cement and better grade of coarse aggregates. The sand is an important part of concrete. It is mainly procured from natural sources. Thus the grade of sand is not under our control. The methods of removing sand from river beds are causing various environmental issues and river sand is depleting at a faster rate than it is replaced by natural methods. Hence, various replacements for the river sand are being done, one of which is manufactured-sand. It is obtained from various granite quarries. Manufactured-sand or M-sand is slowly replacing the fine aggregate in the concrete as the sand is well graded and gives higher strength of concrete. There are various fibers used for reinforcing concrete which consist mainly of artificial or steel fibers. Some of these fibers are quite costly and sometimes difficult to obtain. So there are many natural fibers which can be used in place of these fibers, one of which is coconut fiber, extracted from the shell of a coconut. Coconut fibers are used in various industries like rope making, coir mattresses etc. Since these fibers are one of the strongest fibers among naturally occuring fibers, they can be used in the concrete mix to increase the resistance in concrete. They are also light weight and easily available and thus can be used in reinforcement of concrete. The studies up till now have tested the use of coconut fibers in normal concrete involving river sand but in this study a particular ratio of M-sand and river sand is used to get the maximum possible strength. Hence, in this project an attempt was made to use M-sand and coconut fiber in concrete. Based on the test results, it can be concluded that combination of M-sand and coconut fibers gave favorable results in strength criteria.

  2. Preparation and characterization of poly(acrylic acid)—corn starch blend for use as chemical sand-fixing materials

    Science.gov (United States)

    Dang, Xugang; Chen, Hui; Shan, Zhihua

    2017-07-01

    One chemical sand-fixing materials based on poly(acrylic acid)-corn starch (PACS) blend was studied in this work. The PACS blend was prepared by solution mixing method between PA and CS. In order to prepare sand-fixing materials for environmental applications using the well-established method of spraying evenly PACS blend solution on the surfaces of fine sand. Fourier transform infrared spectroscopy (FT-IR) revealed the existence of the intermolecular interactions between the blend components. Scanning electron microscope (SEM) analysis showed a continuous phase of blend, and it also showed the good sand-fixing capacity. The test results of hygroscopicity and water retention experiments indicated that the blends had excellent water-absorbing and water-retention capacity. The results of contact angle measurements between the PACS solutions and fine sand showed that the PACS blend has a satisfactory effect on fine sand wetting. And the PACS, as a sand-fixation material, has excellent sand-fixation rate up to 99.5%.

  3. Impact of fugitive bitumen on polymer-based flocculation of mature fine tailings

    OpenAIRE

    Klein, C; Harbottle, D; Alagha, L; Xu, Z

    2013-01-01

    In bitumen recovery from oil sands, a percentage of the bitumen is lost to tailings. The effect of fugitive bitumen on fines settling and consolidation in tailings ponds remains controversial. In the current study, the settling performance of mature fine tailings (MFT) in response to flocculant addition was considered by studying MFT of varying bitumen content. Bitumen content in the MFT was adjusted by controlled removal of bitumen using a Denver flotation cell. The initial settling rate of ...

  4. 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…

  5. V-2 at White Sands

    Science.gov (United States)

    1947-01-01

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

  6. Influence of limestone waste as partial replacement material for sand and marble powder in concrete properties

    Directory of Open Access Journals (Sweden)

    Omar M. Omar

    2012-12-01

    Full Text Available Green concrete are generally composed of recycling materials as hundred or partial percent substitutes for aggregate, cement, and admixture in concrete. Limestone waste is obtained as a by-product during the production of aggregates through the crushing process of rocks in rubble crusher units. Using quarry waste as a substitute of sand in construction materials would resolve the environmental problems caused by the large-scale depletion of the natural sources of river and mining sands. This paper reports the experimental study undertaken to investigate the influence of partial replacement of sand with limestone waste (LSW, with marble powder (M.P as an additive on the concrete properties. The replacement proportion of sand with limestone waste, 25%, 50%, and 75% were practiced in the concrete mixes except in the concrete mix. Besides, proportions of 5%, 10% and 15% marble powder were practiced in the concrete mixes. The effects of limestone waste as fine aggregate on several fresh and hardened properties of the concretes were investigated. The investigation included testing of compressive strength, indirect tensile strength, flexural strength, modulus of elasticity, and permeability. It was found that limestone waste as fine aggregate enhanced the slump test of the fresh concretes. But the unit weight concretes were not affected. However, the good performance was observed when limestone waste as fine aggregate was used in presence of marble powder.

  7. 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...

  8. Imeilus Fine 5

    Index Scriptorium Estoniae

    2017-01-01

    Vaba Lava teatrikeskuse laval esineb Fine 5 oma lavastusega "Imeilus". Tiina Ollesk ja Renee Nõmmik, tantsulavastuse autorid on koreograafid, õppejõud, lavastajad ja kogemustega tantsijad. 29. jaanuaril korraldavad Tiina Ollesk ja Renee Nõmmik Tallinna Ülikoolis kaasaegse liikumismõtlemise töötoa, mis on pühendatud lavastusele "Imeilus"

  9. The Fine Dutch Tradition

    NARCIS (Netherlands)

    Hooimeijer, F.L.

    2012-01-01

    Publication of the exhibition and symposium on water adaptive urban planning and architecture in Bangkok. The Urban Fine Dutch Tradition is a dynamic tradition of making urban designs using the parameters of the natural system – incorperating in an efficient way the hydrological cycle, the soil and

  10. Transport of reservoir fines

    DEFF Research Database (Denmark)

    Yuan, Hao; Shapiro, Alexander; Stenby, Erling Halfdan

    Modeling transport of reservoir fines is of great importance for evaluating the damage of production wells and infectivity decline. The conventional methodology accounts for neither the formation heterogeneity around the wells nor the reservoir fines’ heterogeneity. We have developed an integral...

  11. A fine art

    Energy Technology Data Exchange (ETDEWEB)

    Schnabel, G.; Raaff, T. [Andritz AG (Austria)

    2006-07-15

    The paper describes a new dewatering system for coal fines which challenges established processes by using screenbowl centrifuge and hyperbaric filter combinations. Company acquisitions over the past three to four years enabled Andritz AG to develop a new system combining two technologies. The article describes the benefits of the combination process and explains the basic operation of these machines. 4 figs.

  12. Fine 5 lavastab Venemaal

    Index Scriptorium Estoniae

    2013-01-01

    Tantsuteatru Fine 5 koreograafid Tiina Ollesk ja Rene Nõmmik toovad Jekaterinburgis välja lavastuse "... and Red", esitajaks Venemaa nimekas nüüdistantsutrupp Provintsialnõje Tantsõ. Lavastuses kõlab Taavo Remmeli kontrabassiimprovisatsioon "12.12.2006"

  13. Particle size distribution and property of bacteria attached to carbon fines in drinking water treatment

    Directory of Open Access Journals (Sweden)

    Wang Leilei

    2008-06-01

    Full Text Available The quantitative change and size distribution of particles in the effluents from a sand filter and a granular activated carbon (GAC filter in a drinking water treatment plant were investigated. The average total concentration of particles in the sand filter effluent during a filter cycle was 148 particles/mL, 27 of which were larger than 2 µm in size. The concentration in the GAC effluent (561 particles/mL was significantly greater than that in the sand filter effluent. The concentration of particles larger than 2 µm in the GAC filter effluent reached 201 particles/mL, with the amount of particles with sizes between 2 µm and 15 µm increasing. The most probable number (MPN of carbon fines reached 43 unit/L after six hours and fines between 0.45 µm and 8.0 µm accounted for more than 50%. The total concentration of outflowing bacteria in the GAC filter effluent, 350 CFU (colony-forming units/mL, was greater than that in the sand filter effluent, 210 CFU/mL. The desorbed bacteria concentration reached an average of 310 CFU/mg fines. The disinfection efficiency of desorbed bacteria was lower than 40% with 1.5 mg/L of chlorine. The disinfection effect showed that the inactivation rate with 2.0 mg/L of chloramine (90% was higher than that with chlorine (70%. Experimental results indicated that the high particle concentration in raw water and sedimentation effluent led to high levels of outflowing particles in the sand filter effluent. The activated carbon fines in the effluent accounted for a small proportion of the total particle amount, but the existing bacteria attached to carbon fines may influence the drinking water safety. The disinfection efficiency of desorbed bacteria was lower than that of free bacteria with chlorine, and the disinfection effect on bacteria attached to carbon fines with chloramine was better than that with only chlorine.

  14. Landsat-Derived Estimates of Mangrove Extents in the Sierra Leone Coastal Landscape Complex during 1990–2016

    Science.gov (United States)

    Trzaska, Sylwia

    2017-01-01

    This study provides the first assessment of decadal changes in mangrove extents in Sierra Leone. While significant advances have been made in mangrove mapping using remote sensing, no study has documented long-term changes in mangrove extents in Sierra Leone—one of the most vulnerable countries in West Africa. Such understanding is critical for devising regional management strategies that can support local livelihoods. We utilize multi-date Landsat data and cloud computational techniques to quantify spatiotemporal changes in land cover, with focus on mangrove ecosystems, for 1990–2016 along the coast of Sierra Leone. We specifically focus on four estuaries—Scarcies, Sierra Leone, Yawri Bay, and Sherbro. We relied on the k-means approach for an unsupervised classification, and validated the classified map from 2016 using ground truth data collected from Sentinel-2 and high-resolution images and during field research (accuracy: 95%). Our findings indicate that the Scarcies river estuary witnessed the greatest mangrove loss since 1990 (45%), while the Sierra Leone river estuary experienced mangrove gain over the last 26 years (22%). Overall, the Sierra Leone coast lost 25% of its mangroves between 1990 and 2016, with the lowest coverage in 2000, during the period of civil war (1991–2002). However, natural mangrove dynamics, as supported by field observations, indicate the potential for regeneration and sustainability under carefully constructed management strategies. PMID:29267247

  15. SHAPE ANALYSIS OF FINE AGGREGATES USED FOR CONCRETE

    Directory of Open Access Journals (Sweden)

    Huan He

    2016-12-01

    Full Text Available Fine aggregate is one of the essential components in concrete and significantly influences the material properties. As parts of natures, physical characteristics of fine aggregate are highly relevant to its behaviors in concrete. The most of previous studies are mainly focused on the physical properties of coarse aggregate due to the equipment limitations. In this paper, two typical fine aggregates, i.e. river sand and crushed rock, are selected for shape characterization. The new developed digital image analysis systems are employed as the main approaches for the purpose. Some other technical methods, e.g. sieve test, laser diffraction method are also used for the comparable references. Shape characteristics of fine aggregates with different origins but in similar size ranges are revealed by this study. Compared with coarse aggregate, fine grains of different origins generally have similar shape differences. These differences are more significant in surface texture properties, which can be easily identified by an advanced shape parameter: bluntness. The new image analysis method is then approved to be efficient for the shape characterization of fine aggregate in concrete.

  16. experimental studies of sand production from unconsolidated

    African Journals Online (AJOL)

    ES Obe

    mation with some appreciable sand content. This field suffers a continuous sand produc- tion problem. Therefore, a complete research plan was proposed to choose the best sand control method to be applied to the oil field under consideration. The main objective of the plan is presented below. It consists of the following:.

  17. Territorial identity and landscape. Evolution morphology of nuclei in Castilla y Leon; Identidad territorial y paisaje. Evolucion morfologica de los nucleos en Castilla y Leon

    Energy Technology Data Exchange (ETDEWEB)

    Cortes Pedrosa, J.

    2015-07-01

    This paper aims to study the physical and socioeconomic transformations of rural settlements belonging to the Spanish region of Castile and Leon, throughout the second half of the 20th century. The evolution of urban form is analyzed, using a geographical information system (GIS) and calculating several shape metrics, and is then related to historical demographical data. The results are meant to show the effects of functional specialization, caused by the integration of rural regions in global economic hierarchies, on settlement structures and patterns. Gradual loss of the traditional features of Castilian villages, such as urban compactness and integration in the landscape, due to the disappearance or neglect of vernacular architecture and the construction of new industrial infrastructures, poses a risk for future place-based development policies. It is deemed necessary to preserve local identity and avoid destruction or degradation of the traditional heritage for revitalizing these territories. (Author)

  18. Designing fine aggregate mixtures to evaluate fatigue crack-growth in asphalt mixtures.

    Science.gov (United States)

    2011-04-01

    Fatigue cracking is a significant form of pavement distress in flexible pavements. The properties of the : sand-asphalt mortars or fine aggregate matrix (FAM) can be used to characterize the evolution of fatigue : crack growth and self-healing in asp...

  19. The effect of flocculant on the geotechnical properties of mature fine tailings : An experimental study

    NARCIS (Netherlands)

    Yao, Y.; Van Tol, A.F.; Van Paassen, L.A.

    2012-01-01

    When oil sands tailings are deposited in a tailing pond, they settle and segregate to create a layer of stagnant water on top that is reused in oil extraction and a dense mixture of clay, silt and water on the bottom which is referred to as mature fine tailings (MFT). Dewatering of MFT is a problem

  20. Suitability of iron ore tailings and quarry dust as fine aggregates for ...

    African Journals Online (AJOL)

    Experiments were conducted to determine the suitability of iron ore tailings and quarry dust as fine aggregates replacement of river sand for concrete production, and thereby to utilize the enormous quantities of wastes from Itakpe mines and the numerous granite quarries in Nigeria to address concerns of environmental ...

  1. suitability of broken bottles as fine aggregate for production of concrete

    African Journals Online (AJOL)

    user

    The use of broken bottles as partial replacement of river sand for production of concrete was ... material made up of cement, aggregates (fine ... as waste. Their use will reduce the nuisance they cause to man. It is therefore necessary to conduct researches on broken bottles with the view to finding ways they can be useful to ...

  2. The Impact of the West Africa Ebola Outbreak on Obstetric Health Care in Sierra Leone.

    Directory of Open Access Journals (Sweden)

    Kim J Brolin Ribacke

    Full Text Available As Sierra Leone celebrates the end of the Ebola Virus Disease (EVD outbreak, we can begin to fully grasp its impact on already weak health systems. The EVD outbreak in West Africa forced many hospitals to close down or reduce their activity, either to prevent nosocomial transmission or because of staff shortages. The aim of this study is to assess the potential impact of EVD on nationwide access to obstetric care in Sierra Leone.Community health officers collected weekly data between January 2014-May 2015 on in-hospital deliveries and caesarean sections (C-sections from all open facilities (public, private for-profit and private non-profit sectors offering emergency obstetrics in Sierra Leone. This was compared to official data of EVD cases per district. Logistic and Poisson regression analyses were used to compute risk and rate estimates. Nationwide, the number of in-hospital deliveries and C-sections decreased by over 20% during the EVD outbreak. The decline occurred early on in the EVD outbreak and was mainly attributable to the closing of private not-for-profit hospitals rather than government facilities. Due to difficulties in collecting data in the midst of an epidemic, limitations of this study include some missing data points.Both the number of in-hospital deliveries and C-sections substantially declined shortly after the onset of the EVD outbreak. Since access to emergency obstetric care, like C-sections, is associated with decreased maternal mortality, many women are likely to have died due to the reduced access to appropriate care during childbirth. Future research on indirect health effects of health system breakdown should ideally be nationwide and continue also into the recovery phase. It is also important to understand the mechanisms behind the deterioration so that important health services can be reestablished.

  3. Uranium series isotopes concentration in sediments at San Marcos and Luis L. Leon reservoirs, Chihuahua, Mexico

    International Nuclear Information System (INIS)

    Méndez-García, C.; Montero-Cabrera, M. E.; Renteria-Villalobos, M.; García-Tenorio, R.

    2014-01-01

    Spatial and temporal distribution of the radioisotopes concentrations were determined in sediments near the surface and core samples extracted from two reservoirs located in an arid region close to Chihuahua City, Mexico. At San Marcos reservoir one core was studied, while from Luis L. Leon reservoir one core from the entrance and another one close to the wall were investigated. 232 Th-series, 238 U-series, 40 K and 137 Cs activity concentrations (AC, Bq kg −1 ) were determined by gamma spectrometry with a high purity Ge detector. 238 U and 234 U ACs were obtained by liquid scintillation and alpha spectrometry with a surface barrier detector. Dating of core sediments was performed applying CRS method to 210 Pb activities. Results were verified by 137 Cs AC. Resulting activity concentrations were compared among corresponding surface and core sediments. High 238 U-series AC values were found in sediments from San Marcos reservoir, because this site is located close to the Victorino uranium deposit. Low AC values found in Luis L. Leon reservoir suggest that the uranium present in the source of the Sacramento – Chuviscar Rivers is not transported up to the Conchos River. Activity ratios (AR) 234 U/ 238 U and 238 U/ 226 Ra in sediments have values between 0.9–1.2, showing a behavior close to radioactive equilibrium in the entire basin. 232 Th/ 238 U, 228 Ra/ 226 Ra ARs are witnesses of the different geological origin of sediments from San Marcos and Luis L. Leon reservoirs

  4. Uranium series isotopes concentration in sediments at San Marcos and Luis L. Leon reservoirs, Chihuahua, Mexico

    Science.gov (United States)

    Méndez-García, C.; Renteria-Villalobos, M.; García-Tenorio, R.; Montero-Cabrera, M. E.

    2014-07-01

    Spatial and temporal distribution of the radioisotopes concentrations were determined in sediments near the surface and core samples extracted from two reservoirs located in an arid region close to Chihuahua City, Mexico. At San Marcos reservoir one core was studied, while from Luis L. Leon reservoir one core from the entrance and another one close to the wall were investigated. 232Th-series, 238U-series, 40K and 137Cs activity concentrations (AC, Bq kg-1) were determined by gamma spectrometry with a high purity Ge detector. 238U and 234U ACs were obtained by liquid scintillation and alpha spectrometry with a surface barrier detector. Dating of core sediments was performed applying CRS method to 210Pb activities. Results were verified by 137Cs AC. Resulting activity concentrations were compared among corresponding surface and core sediments. High 238U-series AC values were found in sediments from San Marcos reservoir, because this site is located close to the Victorino uranium deposit. Low AC values found in Luis L. Leon reservoir suggest that the uranium present in the source of the Sacramento - Chuviscar Rivers is not transported up to the Conchos River. Activity ratios (AR) 234U/overflow="scroll">238U and 238U/overflow="scroll">226Ra in sediments have values between 0.9-1.2, showing a behavior close to radioactive equilibrium in the entire basin. 232Th/overflow="scroll">238U, 228Ra/overflow="scroll">226Ra ARs are witnesses of the different geological origin of sediments from San Marcos and Luis L. Leon reservoirs.

  5. Clinical illness and outcomes in patients with Ebola in Sierra Leone.

    Science.gov (United States)

    Schieffelin, John S; Shaffer, Jeffrey G; Goba, Augustine; Gbakie, Michael; Gire, Stephen K; Colubri, Andres; Sealfon, Rachel S G; Kanneh, Lansana; Moigboi, Alex; Momoh, Mambu; Fullah, Mohammed; Moses, Lina M; Brown, Bethany L; Andersen, Kristian G; Winnicki, Sarah; Schaffner, Stephen F; Park, Daniel J; Yozwiak, Nathan L; Jiang, Pan-Pan; Kargbo, David; Jalloh, Simbirie; Fonnie, Mbalu; Sinnah, Vandi; French, Issa; Kovoma, Alice; Kamara, Fatima K; Tucker, Veronica; Konuwa, Edwin; Sellu, Josephine; Mustapha, Ibrahim; Foday, Momoh; Yillah, Mohamed; Kanneh, Franklyn; Saffa, Sidiki; Massally, James L B; Boisen, Matt L; Branco, Luis M; Vandi, Mohamed A; Grant, Donald S; Happi, Christian; Gevao, Sahr M; Fletcher, Thomas E; Fowler, Robert A; Bausch, Daniel G; Sabeti, Pardis C; Khan, S Humarr; Garry, Robert F

    2014-11-27

    Limited clinical and laboratory data are available on patients with Ebola virus disease (EVD). The Kenema Government Hospital in Sierra Leone, which had an existing infrastructure for research regarding viral hemorrhagic fever, has received and cared for patients with EVD since the beginning of the outbreak in Sierra Leone in May 2014. We reviewed available epidemiologic, clinical, and laboratory records of patients in whom EVD was diagnosed between May 25 and June 18, 2014. We used quantitative reverse-transcriptase-polymerase-chain-reaction assays to assess the load of Ebola virus (EBOV, Zaire species) in a subgroup of patients. Of 106 patients in whom EVD was diagnosed, 87 had a known outcome, and 44 had detailed clinical information available. The incubation period was estimated to be 6 to 12 days, and the case fatality rate was 74%. Common findings at presentation included fever (in 89% of the patients), headache (in 80%), weakness (in 66%), dizziness (in 60%), diarrhea (in 51%), abdominal pain (in 40%), and vomiting (in 34%). Clinical and laboratory factors at presentation that were associated with a fatal outcome included fever, weakness, dizziness, diarrhea, and elevated levels of blood urea nitrogen, aspartate aminotransferase, and creatinine. Exploratory analyses indicated that patients under the age of 21 years had a lower case fatality rate than those over the age of 45 years (57% vs. 94%, P=0.03), and patients presenting with fewer than 100,000 EBOV copies per milliliter had a lower case fatality rate than those with 10 million EBOV copies per milliliter or more (33% vs. 94%, P=0.003). Bleeding occurred in only 1 patient. The incubation period and case fatality rate among patients with EVD in Sierra Leone are similar to those observed elsewhere in the 2014 outbreak and in previous outbreaks. Although bleeding was an infrequent finding, diarrhea and other gastrointestinal manifestations were common. (Funded by the National Institutes of Health and

  6. Uranium series isotopes concentration in sediments at San Marcos and Luis L. Leon reservoirs, Chihuahua, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Méndez-García, C.; Montero-Cabrera, M. E., E-mail: elena.montero@cimav.edu.mx [Centro de Investigación en Materiales Avanzados, CIMAV, Miguel de Cervantes 120, 31109, Chihuahua, Chihuahua (Mexico); Renteria-Villalobos, M. [Facultad de Zootecnia y Ecología Universidad Autónoma de Chihuahua, Periferico Francisco R. Almada Km 1, 31410, Chihuahua (Mexico); García-Tenorio, R. [Applied Nuclear Physics Group, University of Seville, ETS Arquitectura, Avda. Reina Mercedes s/n, 41012 Seville (Spain)

    2008-01-01

    Spatial and temporal distribution of the radioisotopes concentrations were determined in sediments near the surface and core samples extracted from two reservoirs located in an arid region close to Chihuahua City, Mexico. At San Marcos reservoir one core was studied, while from Luis L. Leon reservoir one core from the entrance and another one close to the wall were investigated. ²³²Th-series, ²³⁸U-series, ⁴⁰K and ¹³⁷Cs activity concentrations (AC, Bq kg⁻¹) were determined by gamma spectrometry with a high purity Ge detector. ²³⁸U and ²³⁴U ACs were obtained by liquid scintillation and alpha spectrometry with a surface barrier detector. Dating of core sediments was performed applying CRS method to ²¹⁰Pb activities. Results were verified by ¹³⁷Cs AC. Resulting activity concentrations were compared among corresponding surface and core sediments. High ²³⁸U-series AC values were found in sediments from San Marcos reservoir, because this site is located close to the Victorino uranium deposit. Low AC values found in Luis L. Leon reservoir suggest that the uranium present in the source of the Sacramento – Chuviscar Rivers is not transported up to the Conchos River. Activity ratios (AR) ²³⁴U/²³⁸U and ²³⁸U/²²⁶Ra in sediments have values between 0.9–1.2, showing a behavior close to radioactive equilibrium in the entire basin. ²³²Th/²³⁸U, ²²⁸Ra/²²⁶Ra ARs are witnesses of the different geological origin of sediments from San Marcos and Luis L. Leon reservoirs.

  7. Retention of health workers in rural Sierra Leone: findings from life histories.

    Science.gov (United States)

    Wurie, Haja R; Samai, Mohamed; Witter, Sophie

    2016-02-01

    Sierra Leone has faced a shortage and maldistribution of staff in its post-conflict period. This long-standing challenge is now exacerbated by the systemic shock and damage wrought by Ebola. This study aimed to investigate the importance of different motivation factors in rural areas in Sierra Leone and thus to contribute to better decisions on financial and non-financial incentive packages, here and in similar contexts. This article is based on participatory life histories, conducted in 2013 with 23 health workers (doctors, nurses, midwives and Community Health Officers) in four regions of Sierra Leone who had worked in the sector since 2000. Although the interviews covered a wide range of themes, here we present findings on motivating and demotivating factors for staff, especially those in rural areas, based on thematic analysis of transcripts. Rural health workers face particular challenges, some of which stem from the difficult terrain, which add to common disadvantages of rural living (poor social amenities, etc.). Poor working conditions, emotional and financial costs of separation from families, limited access to training, longer working hours (due to staff shortages) and the inability to earn from other sources make working in rural areas less attractive. Moreover, rules on rotation which should protect staff from being left too long in rural areas are not reported to be respected. By contrast, poor management had more resonance in urban areas, with reports of poor delegation, favouritism and a lack of autonomy for staff. Tensions within the team over unclear roles and absenteeism are also significant demotivating factors in general. This study provides important policy-focused insights into motivation of health workers and can contribute towards building a resilient and responsive health system, incorporating the priorities and needs of health workers. Their voices and experiences should be taken into account as the post-Ebola landscape is shaped.

  8. Reframing the Canadian Oil Sands

    OpenAIRE

    Patchett, Merle M; Lozowy, A

    2012-01-01

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

  9. Thermal Properties of oil sand

    Science.gov (United States)

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

    2013-12-01

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

  10. Sea sand for reactive barriers

    International Nuclear Information System (INIS)

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

    2002-01-01

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

  11. 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.

  12. Properties of concrete containing ground palm oil fuel ash as fine aggregate replacement

    Science.gov (United States)

    Saffuan, W. A.; Muthusamy, K.; Salleh, N. A. Mohd; Nordin, N.

    2017-11-01

    Environmental degradation resulting from increasing sand mining activities and disposal of palm oil fuel ash (POFA), a solid waste generated from palm oil mill needs to be resolved. Thus, the present research investigates the effect of ground palm oil fuel ash as partial fine aggregate replacement on workability, compressive and flexural strength of concrete. Five mixtures of concrete containing POFA as partial sand replacement designed with 0%, 10%, 20%, 30% and 40% of POFA by the weight of sand were used in this experimental work. The cube and beam specimens were casted and water cured up to 28 days before subjected to compressive strength and flexural strength testing respectively. Finding shows that concrete workability reduces as the amount of POFA added become larger. It is worth to note that 10% of POFA is the best amount to be used as partial fine aggregate replacement to produce concrete with enhanced strength.

  13. Rheological Characterization of Green Sand Flow

    DEFF Research Database (Denmark)

    Jabbaribehnam, Mirmasoud; Spangenberg, Jon; Hovad, Emil

    2016-01-01

    The main aim of this paper is to characterize experimentally the flow behaviour of the green sand that is used for casting of sand moulds. After the sand casting process is performed, the sand moulds are used for metal castings. The rheological properties of the green sand is important to quantify...... module for characterizing granular materials. The new module enables viscosity measurements of the green sand as function of the shear rate at different flow rates, i.e. 0, 2, 4, 6, 8, 10, 12 and 15 L/min. The results show generally that the viscosity decreases with both the shear- and flow rate....... In addition, the measurements show that the green sand flow follows a shear-thinning behaviour even after the full fluidization point....

  14. Cemented Backfilling Technology of Paste-Like Based on Aeolian Sand and Tailings

    Directory of Open Access Journals (Sweden)

    Qinli Zhang

    2016-12-01

    Full Text Available Aeolian sand, tailings, and #32.5 Portland cement were used to produce backfilling aggregate, and physicochemical evaluations and proportioning tests were conducted. It is revealed that a mixture of aeolian sand and tailings can be used as a backfilling aggregate for the complementarities of their physicochemical properties; e.g., high Al2O3 content in the aeolian sand and CaO content in the tailings, coarse particles of aeolian sand and fine particles of tailings, etc. In addition, the optimal backfilling aggregate was shown to have a mass fraction of 72%–74%, a cement–sand ratio of 1:8, and an aeolian sand proportion of 25%. Furthermore, viscometer tests were used to analyze the rheological characteristics, and the slurry in these optimized proportions exhibited shear thinning phenomena with an initial yield stress, which belongs to paste-like—a cemented backfilling slurry with a higher mass fraction than a two-phase flow and better flowability than a paste slurry. Finally, the application of this backfilling technology shows that it can not only realize safe mining, but also bring huge economic benefits, and has some constructive guidance for environmental protection.

  15. Crushed and River-Origin Sands Used as Aggregates in Repair Mortars

    Directory of Open Access Journals (Sweden)

    Maria Stefanidou

    2016-04-01

    Full Text Available The systematic analysis of mortars from monuments or historic buildings and the simultaneous study of the construction environment show that it was common practice to use naturally occurring sand from local rivers or streams for the production of the mortars. There are cases though, mainly on islands, where sands of natural origin were limited, and marine or crushed sands were used possibly after elaboration. In all cases the particle size analysis of old mortar confirms the presence of even distribution of the granules. As regards the design of the repair mortars, there are criteria that should be taken into consideration in order to produce materials with compatible properties. The main properties concerning sands are the grain distribution and maximum size, the color, the content of fines, and soluble salts. The objective of this research is the study of the physical characteristics of the sands such as the sand equivalent, the gradation, the apparent density, the morphology of the grains, their mineralogical composition and the influence of these properties on the behavior of lime mortars, notably the mechanical and physical properties acquired.

  16. Experiences of attitudes in Sierra Leone from the perspective of people with poliomyelitis and amputations using orthotics and prosthetics.

    Science.gov (United States)

    Andregård, Emmelie; Magnusson, Lina

    2017-12-01

    The aim of this study was to describe experiences of attitudes in the society of Sierra Leone from the perspective of individuals with poliomyelitis and people with amputations using orthotic or prosthetic devices. Individual interviews were conducted using open-ended questions. Twelve participants with amputations or polio were included. Content analysis was applied to the data. The following six themes emerged during data analysis: Experience of negative attitudes; Neglected and respected by family; Traditional beliefs; The importance of assistive devices; People with disability struggle with poverty; and The need for governmental and international support. In Sierra Leone, people with disabilities face severe discrimination. They need to be included, recognized, and supported to a greater extent by the society, the community, and the family, as well as by the government and international organizations. Traditional beliefs have a negative impact on people with physical disabilities and are an important cause of discrimination in Sierra Leone. Prosthetic and orthotic devices are vital for people with physical disability and offer increased dignity. Prosthetic and orthotic services need to be accessible and affordable. Poverty affects access to education, employment, and health care for Sierra Leoneans with physical disabilities, forcing them to resort to begging to cover basic living needs. Implications for Rehabilitation In Sierra Leone, traditional beliefs related to disability and public attitudes need to change in order to protect the human rights of people with disabilities. Increased public awareness of disability and implementation of the United Nations Convention on the Rights of Persons with Disabilities (CRPD) at different levels in society is needed. To increase access to prosthetic and orthotic services in Sierra Leone, these services need to be affordable and related costs, such as transport, need to be covered by support. Increased access to

  17. THE IMPORTANCE OF THE JURIST AND ECONOMIST GHEORGHE N. LEON IN THE EVOLUTION OF FINANCIAL SCIENCE

    Directory of Open Access Journals (Sweden)

    Popa Carmen

    2011-07-01

    Full Text Available The economical-financial problems have always constituted a challenge far all the decisional factors at the state level and not only, thus the financial sciences which also aim to regulate the relationships to create, assign and use the financial funds of the state and of the public institutions, destined to satisfy the social-economical needs of the society recorded a great doctrinal interest. Thus, a series of jurists and economists had understand the necessity and opportunity of knowledge in the domain of financial science, of the financial law, taking into consideration the fact that the difficulties which they have met at those times obliged them to take the responsibility to make every simple citizen and every person with political or administrative responsibility by the state understand the problems of public administration. In approaching the given subject I have chosen to use some of the methods of scientific research, respectively: the historical method (financial science being presented succinct through the process of its evolution along the years, interpretation methods and a combination of quality and quantity approach, namely the method of analyzing archive documents and the studies of professor Gheorghe N. Leon. In these contexts have asserted and developed himself in the university and political environment, Gheorghe N. Leon, having a rich activity of intellectual creation, approaching in his works the complex aspects of the science of financial law. Thus, starting with the rules and principles of this domain, Gheorghe N. Leon had realized a veritable incursion in the history of finances and in the theory of taxation, public and budgetary credit. Analyzing a part of his scientific works, we can affirm that a personality with such a complex structure, like Gheorghe N. Leon is hard to define, but surely, through the prism of his works and through his long-lasting and rich scientific activity, his name can be mentioned among the

  18. The Ebola virus disease outbreak and the mineral sectors of Guinea, Liberia, and Sierra Leone

    Science.gov (United States)

    Bermúdez-Lugo, Omayra; Menzie, William D.

    2015-01-01

    The mineral sector plays a key role in the economies of Guinea, Liberia, and Sierra Leone. The onset of the Ebola virus disease (EVD) outbreak in early 2014, together with changes in mineral market conditions, raised questions regarding the status of mining operations and of mineral development and exploration projects in all three countries. Mineral projects were the underpinnings of World Bank short-term forecasts of increases in gross domestic product (GDP) for all three countries and were expected to be the basis of future economic growth. The significant delay or cancellation of these projects could result in a major economic setback for all three countries.

  19. The Pious Schools in Castille and Leon (1875-1931:Social and educative view

    Directory of Open Access Journals (Sweden)

    Bienvenido MARTÍN FRAILE

    2013-11-01

    Full Text Available The present historiographie research on the Pious Schools in Castille and Leon during the Bourbon Restoration has studied the public, institutional and social dimensions of these centres. The liberal revolutions of the nineteenth century defended the escolapios and even let them expand to such an extent that the end of the century they increased considerably. If it happened so it was because its educative work brought great benefits to the State as well as the citizens. Therefore, there was a symbiosis between the unimaginable in other teaching institutions.

  20. Vision to Reality: From Robert R. Wilson's Frontier to Leon M. Lederman's Fermilab

    Science.gov (United States)

    Hoddeson, Lilian; Kolb, Adrienne

    We examine the roles of vision and leadership in creating and directing Fermi National Accelerator Laboratory from the late 1960s through the 1980s. The story divides into two administrations having different problems and accomplishments, that of Robert R. Wilson from 1967-1978, which saw the transformation from cornfield to frontier physics facility, and that of Leon M. Lederman from 1979-1989, in which the laboratory evolved into one of the world's major high-energy facilities. Lederman's pragmatic vision of a user-based experimental community helped him to convert the pioneering facility that Wilson had built frugally into a laboratory with a stable scientific, cultural, and funding environment.

  1. Post acquisition business synergies of a foreign affiliate. Case study of companies in Nuevo Leon

    Directory of Open Access Journals (Sweden)

    Luis Cabeza

    2016-09-01

    Full Text Available This article will explain the importance of creating synergies after having acquired foreign affiliates. Interviews were conducted to executives of four of the most important manufacturing companies in Nuevo Leon, which have been involved in the international acquisition process of foreign affiliates. Also presented are 10 areas where synergies may be obtained after having acquired a foreign affiliate, in accordance with (Marin and Ketelhohn, 2008 economies of size at corporate headquarters, greater opportunities for professional development, corporate image, interdivisional transactions, vertical integration, economies of scale and/or scope, coordination of skills, learning center, leverage of intangible assets and unleashing of skills.

  2. Reasons to pursue a career in medicine: a qualitative study in Sierra Leone.

    Science.gov (United States)

    Woodward, Aniek; Thomas, Suzanne; Jalloh, Mohamed Bella; Rees, John; Leather, Andrew

    2017-01-01

    Many low-income and crises-affected countries like Sierra Leone struggle with the recruitment and retention of their health professionals, particularly nurses and doctors. There are multiple factors that influence the 'recruitment to retention' pipeline. The first stage of an exploration into the issues influencing the availability of qualified health care workers may focus on the aspects which influence their entry into relevant educational programmes. This paper explores the reasons given by junior doctors in Sierra Leone for wanting to become a doctor. It also describes entry procedures into undergraduate medical education. In-depth interviews were conducted with purposively sampled junior doctors ( n  = 15) from the only medical school in Sierra Leone in October 2013. Digital diaries and two follow-up interviews were used to explore their evolving career experiences and aspirations until November 2016. In addition, semi-structured interviews with key informants ( n  = 20), including senior teaching staff at the medical school ( n  = 7), were conducted. Thematic analysis was used to explore linkages and themes across cases. Six themes were identified. The most commonly mentioned reasons for wanting to become a doctor were a desire to help (theme 4) and the influence of family and friends, via role modelling (theme 2) and verbal encouragement (theme 3). Other motives were an interest from a young age (theme 1), being attracted by the job prospects (theme 5), and having an intellectual and science capacity (theme 6). Junior doctors gave at least two and up to six reasons for applying to enter the medical profession. Doctors were allowed entry to the medical school largely based on their previous academic performance. This study showed that multiple reasons underlie the decision to apply for entrance to medical school and the decision to enter medicine is complex. These findings may inform the review of future admission procedures by the medical school

  3. Decontamination of Uranium-Contaminated Soil Sand Using Supercritical CO2 with a TBP–HNO3 Complex

    Directory of Open Access Journals (Sweden)

    Kwangheon Park

    2015-09-01

    Full Text Available An environmentally friendly decontamination process for uranium-contaminated soil sand is proposed. The process uses supercritical CO2 as the cleaning solvent and a TBP–HNO3 complex as the reagent. Four types of samples (sea sand and coarse, medium, and fine soil sand were artificially contaminated with uranium. The effects of the amount of the reagent, sand type, and elapsed time after the preparation of the samples on decontamination were examined. The extraction ratios of uranium in all of the four types of sand samples were very high when the time that elapsed after preparation was less than a few days. The extraction ratio of uranium decreased in the soil sand with a higher surface area as the elapsed time increased, indicating the possible formation of chemisorbed uranium on the surface of the samples. The solvent of supercritical CO2 seemed to be very effective in the decontamination of soil sand. However, the extraction of chemisorbed uranium in soil sand may need additional processes, such as the application of mechanical vibration and the addition of bond-breaking reagents.

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

    Science.gov (United States)

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

    2008-01-01

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

  5. Recomendaciones de Liderazgo para los Dueños de Pymes Familiares Exportadoras y no Exportadoras en Nuevo Leon

    Directory of Open Access Journals (Sweden)

    Maria Eloisa Treviño Ayala

    2011-07-01

    Full Text Available The main purpose of this document is to state the importance that small and medium-sized enterprises (SMEs exporting and non-exporting have, as well as family businesses in Mexico´s economy and specifically in the state of Nuevo Leon. It establishes certain family SMEs, exporting and non-exporting, characteristics to take into consideration by Nuevo Leon leaders that seek success under the determinant of profits. It also locates qualities, from our stand point, classic and contemporaries, recommended for managers and administrators of this type of companies.

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

    Science.gov (United States)

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

    2017-09-01

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

  7. Construction report - US Highway 36, superpave overlay of sand anti-fracture layer over AC/PCC pavement.

    Science.gov (United States)

    2000-12-01

    The sand anti-fracture (SAF) technology was implemented on U.S. 36 in DeKalb County, Missouri, during the summer of 2000. The SAF layer is a fine aggregate graded asphalt mixture using highly polymerized asphalt binder that gives the SAF layer the ab...

  8. A laboratory experiment on the evolution of a sand gravel reach under a lack of sediment supply

    NARCIS (Netherlands)

    Orru, C.; Chavarrias Borras, V.; Ferrara, V.; Stecca, G.; Blom, A.

    2015-01-01

    A flume experiment was conducted to examine the evolution of a sand-gravel reach under a lack of sediment supply. A bed composed of a bimodal sediment mixture was installed with a uniform slope and an gradual fining pattern. At the upstream end of the flume the initial bed consisted of 100% gravel,

  9. [Environmental toxicity of waste foundry sand].

    Science.gov (United States)

    Zhang, Hai-Feng; Wang, Yu-Jue; Wang, Jin-Lin; Huang, Tian-You; Xiong, Ying

    2013-03-01

    The metal leaching characteristics and volatile organic compounds (VOCs) of five different types of waste foundry sands were analyzed with the toxicity characteristic leaching procedure (TCLP) and head space-gas chromatography (HS-GC). Microtox and soil dehydrogenase activity (DHA) tests were then used to evaluate the bio-effects of these waste sands. The results showed that due to the different metals poured and casting materials used to make the sand molds, there was significant difference among the five waste foundry sands in the compositions and concentrations of metal and organic pollutants. The concentrations of Fe in the leachates of iron and steel casting waste foundry sand exceeded the maximal allowable concentrations specified in the National Standard of Drinking Water Quality, whereas the As concentration in the leachate of aluminum casting waste foundry sand exceeded the standard. The five waste foundry sands had quite different compositions and levels of VOCs, which resulted in different levels of inhibition effects on the luminescent bacteria (30% and 95%). Additionally, the soil DHA tests suggested that metal pollutants in waste foundry sands may inhibit the soil microbial activity, whereas organics in the sands may slightly promote the microbial activity. The results of this study indicated that the waste foundry sands may pose considerable threat to the environment when improperly disposed.

  10. Abrasive Erosion Study on S45C Carbon Steel Using Sand Blasting Technique

    Science.gov (United States)

    Naz, Muhammad Yasin; Ismail, Noor Ilyana; Sulaiman, Shaharin Anwar; Shukrullah, Shazia

    2016-05-01

    Hydrocarbon fluids recovered from the reservoir are inevitably polluted with sand particles. Sanding is a source of several flow assurance problems in oil and gas industry. This study was aimed at investigating the effect of sand size and impact angle on the mild steel erosion by using a laboratory built sand blasting technique. S45C mild steel coupons were eroded with 45 μm and 150μm sand particles for fixed exposure time of 1 h. Although in-depth analysis revealed an increase in surface erosion with the particle size, the fine sand also notably damaged the metal surface. Topographic scanning electron microscopy (SEM) and universal scanning electron microscopy (USPM) micrographs of the steel coupons showed significantly large difference between the peak and bottom of the eroded samples as compared to the blank coupon. The erosion rates calculated for 45 and 150 μm sand particles were found in the range of 6.47mm/year to 6.84 mm/year and 8.31 mm/year to 8.79 mm/year, respectively. Additionally, a good agreement was seen among the erosion rates calculated using USPM and weight loss methods. The erosion rates calculated for coarse sand at 45∘ and 90∘ were found in the range of 4.58 mm/year to 4.72 mm/year and 8.31 mm/year to 8.79 mm/year, respectively. A large difference between the angle dependent erosion rates revealed a strong influence of the impact angle on erosion of the flow-lines.

  11. The Effects of Substitution of The Natural Sand by Steel Slag in The Properties of Eco-Friendly Concrete with The 1:2:3 Ratio Mixing Method

    Science.gov (United States)

    Rahmawati, A.; Saputro, I. N.

    2018-03-01

    This study was motivated by the need for the development of eco-friendly concrete, and the use of large quantities of steel slag as an industrial waste which is generated from the steel manufacturers. This eco-friendly concrete was developed with steel slag as a substitute for natural sand. Properties of concrete which used waste slag as the fine aggregate with the 1 cement: 2 sand : 3 coarse aggregate ratio mixing method were examined. That ratio was in volume. Then a part of natural sand replaced with steel slag sand in six variations percentages that were 0 %, 20 %, 40 %, 60 %, 80 % and 100 %. The compressive strength, tensile strength, and flexural strength of concrete specimens were determined after curing for 28 days. The research results demonstrate that waste steel slag can increase the performance of concrete. The optimal percentage substitution natural sand by steel slag sand reached of slag on the percentage of 20 % which reached strength ratios of steel slag concrete to the strength of conventional concrete with natural sandstone were 1.37 for compressive strength and 1.13 for flexural strength. While the tensile strength reached a higher ratio of concrete with steel slag sand to the concrete with natural sand on the 80% substitution of natural sand with steel slag sand.

  12. Study on the durability of concrete using granulated blast furnace slag as fine aggregate

    Science.gov (United States)

    Shi, Dongsheng; Liu, Qiang; Xue, Xinxin; He, Peiyuan

    2018-03-01

    In order to assessing the durability of concrete using granulated blastfurnace slag (GBS) as fine aggregate and compare it with natural river sand concrete, three different size of specimen were produced by using the same mix proportion with 3 different water cement ratios and 3 replacement ratios, and using it to measure the three aspects on the durability of concrete including freeze-thaw performance, dry-shrinkage performance and anti-chloride-permeability performance. In this paper. The test results show that using GBS as fine aggregate can slightly improve anti-chloride-permeability performance and dry-shrinkage performance of concrete in the condition of low water cement ratio, on the other hand, using GBS or natural river sand as fine aggregate has almost similar durability of concrete.

  13. Real exchange rate behaviour and economic growth: evidence from Sierra Leone

    Directory of Open Access Journals (Sweden)

    Abu Tarawalie

    2011-05-01

    Full Text Available The main focus of this paper is to examine the impact of the real effective exchange rate on economic growth in Sierra Leone. First an analytical framework is developed to identify the determinants of the real effective exchange rate. Using quarterly data and employing recent econometric techniques, the relationship between the real effective exchange rate and economic growth is then investigated. A bivariate Granger causality test was also employed as part of the methodology to examine the causal relationship between the real exchange rate and economic growth. The empirical results suggest that the real effective exchange rate correlates positively with economic growth, with a statistically significant coefficient. The results also indicate that monetary policy is relatively more effective than fiscal policy in the long run, and evidence of the real effective exchange rate causing economic growth was profound. In addition, the results showed that terms of trade, exchange rate devaluation, investment to GDP ratio and an excessive supply of domestic credit were the main determinants of the real exchange rate in Sierra Leone.

  14. Ebola Virus Epidemiology, Transmission, and Evolution during Seven Months in Sierra Leone.

    Science.gov (United States)

    Park, Daniel J; Dudas, Gytis; Wohl, Shirlee; Goba, Augustine; Whitmer, Shannon L M; Andersen, Kristian G; Sealfon, Rachel S; Ladner, Jason T; Kugelman, Jeffrey R; Matranga, Christian B; Winnicki, Sarah M; Qu, James; Gire, Stephen K; Gladden-Young, Adrianne; Jalloh, Simbirie; Nosamiefan, Dolo; Yozwiak, Nathan L; Moses, Lina M; Jiang, Pan-Pan; Lin, Aaron E; Schaffner, Stephen F; Bird, Brian; Towner, Jonathan; Mamoh, Mambu; Gbakie, Michael; Kanneh, Lansana; Kargbo, David; Massally, James L B; Kamara, Fatima K; Konuwa, Edwin; Sellu, Josephine; Jalloh, Abdul A; Mustapha, Ibrahim; Foday, Momoh; Yillah, Mohamed; Erickson, Bobbie R; Sealy, Tara; Blau, Dianna; Paddock, Christopher; Brault, Aaron; Amman, Brian; Basile, Jane; Bearden, Scott; Belser, Jessica; Bergeron, Eric; Campbell, Shelley; Chakrabarti, Ayan; Dodd, Kimberly; Flint, Mike; Gibbons, Aridth; Goodman, Christin; Klena, John; McMullan, Laura; Morgan, Laura; Russell, Brandy; Salzer, Johanna; Sanchez, Angela; Wang, David; Jungreis, Irwin; Tomkins-Tinch, Christopher; Kislyuk, Andrey; Lin, Michael F; Chapman, Sinead; MacInnis, Bronwyn; Matthews, Ashley; Bochicchio, James; Hensley, Lisa E; Kuhn, Jens H; Nusbaum, Chad; Schieffelin, John S; Birren, Bruce W; Forget, Marc; Nichol, Stuart T; Palacios, Gustavo F; Ndiaye, Daouda; Happi, Christian; Gevao, Sahr M; Vandi, Mohamed A; Kargbo, Brima; Holmes, Edward C; Bedford, Trevor; Gnirke, Andreas; Ströher, Ute; Rambaut, Andrew; Garry, Robert F; Sabeti, Pardis C

    2015-06-18

    The 2013-2015 Ebola virus disease (EVD) epidemic is caused by the Makona variant of Ebola virus (EBOV). Early in the epidemic, genome sequencing provided insights into virus evolution and transmission and offered important information for outbreak response. Here, we analyze sequences from 232 patients sampled over 7 months in Sierra Leone, along with 86 previously released genomes from earlier in the epidemic. We confirm sustained human-to-human transmission within Sierra Leone and find no evidence for import or export of EBOV across national borders after its initial introduction. Using high-depth replicate sequencing, we observe both host-to-host transmission and recurrent emergence of intrahost genetic variants. We trace the increasing impact of purifying selection in suppressing the accumulation of nonsynonymous mutations over time. Finally, we note changes in the mucin-like domain of EBOV glycoprotein that merit further investigation. These findings clarify the movement of EBOV within the region and describe viral evolution during prolonged human-to-human transmission. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  15. Ebola virus disease: caring for patients in Sierra Leone - a qualitative study.

    Science.gov (United States)

    Andertun, Sara; Hörnsten, Åsa; Hajdarevic, Senada

    2017-03-01

    The aim of this study was to describe Norwegian healthcare staffs' experiences of participating in care of patients with Ebola virus disease in Sierra Leone. Ebola is one of the most feared viruses known. Ebola virus disease is highly contagious with high mortality. The few qualitative studies made on experiences among healthcare professionals have highlighted problems as lack of protective resources, insufficient personnel and risk of societal stigmatization. Descriptive study with qualitative approach. Individual narrative and focus group interviews were obtained during 2015 with eight nurses and one physician who had worked in Ebola care in Sierra Leone. The interviews were analysed using qualitative content analysis. The analysis resulted in the two themes: 'Experiencing security by learning to manage risks'; and 'Developing courage and growth by facing personal fears'. Subthemes were: 'Relying on safeguard actions', 'Managing risk of contagion', 'Developing strategies for care despite risks', 'Constantly reminded of death', 'Successively defeating fears' and last, 'Increasing motivation through meaningfulness'. The participants described the reliance on training, organized effort, strict guidelines and equipment. They were respectful of the risk of transmission, made risk assessments, took responsibility, handled risky situations and were reminded of suffering and death. Despite challenges, the hazardous work with Ebola virus disease patients was experienced as meaningful which was an important motivator. Safe care was central in working with Ebola patients, but the care relation was challenged. © 2016 John Wiley & Sons Ltd.

  16. Maternal and perinatal outcomes in pregnant women with suspected Ebola virus disease in Sierra Leone, 2014.

    Science.gov (United States)

    Lyman, Meghan; Johnson Mpofu, Jonetta; Soud, Fatma; Oduyebo, Titilope; Ellington, Sascha; Schlough, Gabriel W; Koroma, Alimamy P; McFadden, Jevon; Morof, Diane

    2018-03-23

    To describe maternal and perinatal outcomes among pregnant women with suspected Ebola virus disease (EVD) in Sierra Leone. Observational investigation of maternal and perinatal outcomes among pregnant women with suspected EVD from five districts in Sierra Leone from June-December 2014. Suspected cases were ill pregnant women with symptoms suggestive of EVD or relevant exposures who were tested for EVD. Case frequencies and odds ratios were calculated to compare patient characteristics and outcomes by EVD status. There were 192 suspected cases: 67 (34.9%) EVD-positive, 118 (61.5%) EVD-negative, and 7 (3.6%) EVD status unknown. Women with EVD had increased odds of death (OR 10.22; 95% CI, 4.87-21.46) and spontaneous abortion (OR 4.93; 95% CI, 1.79-13.55) compared with those without EVD. Women without EVD had a high frequency of death (30.2%) and stillbirths (65.9%). One of 14 neonates born following EVD-negative and five of six neonates born following EVD-positive pregnancies died. EVD-positive and EVD-negative women with suspected EVD had poor outcomes, highlighting the need for increased attention and resources focused on maternal and perinatal health during an urgent public health response. Capturing pregnancy status in nationwide surveillance of EVD can help improve understanding of disease burden and design effective interventions. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  17. The cost of tuberculosis to patients in Sierra Leone's war zone.

    Science.gov (United States)

    Gibson, N; Boillot, F; Jalloh, H

    1998-09-01

    To evaluate how the extreme poverty of the patients and the poor salaries of the staff combined to increase the cost of treatment to patients within the subsidised national tuberculosis programme in Sierra Leone. From September to December of 1994, semi-structured interviews were conducted with 72 patients and 17 staff of the National Leprosy and Tuberculosis Control Programme of Sierra Leone, a screening and treatment programme funded by international donors. Although some extra costs were indeed incurred within the subsidized national tuberculosis treatment programme, they were much lower than those incurred during the pre-programme period when the patients sought intermittent help from a wide range of traditional and biomedical sources within the plural healing continuum. The national politico-economic crisis, and the consequent poverty of most patients, impeded compliance with and sustainability of treatment, even within the formal subsidised treatment programme. More money was spent by patients on treatment in the months/years preceding entry into the national tuberculosis programme. Many factors retarded entry, including poor communications, misinformation, malpractice by health professionals, and displacement resulting from chronic internal warfare. The war intensified all factors that predispose to tuberculosis and retarded access to treatment. Supra-programme cost, or 'corruption,' was minimal due to the poverty of health professionals, with a few salient exceptions.

  18. Control of Ebola hemorrhagic fever: vaccine development and our Ebola project in Sierra Leone.

    Science.gov (United States)

    Watanabe, Tokiko; Kawaoka, Yoshihiro

    2016-01-01

    Since December 2013, West Africa has experienced the worst Ebola virus outbreak in recorded history. Of the 28,639 cases reported to the World Health Organization as of March 2016, nearly half (14,124) occurred in Sierra Leone. With a case fatality rate of approximately 40%, this outbreak has claimed the lives of 11,316 individuals. No FDA-approved vaccines or drugs are available to prevent or treat Ebola virus infection. Experimental vaccines and therapies are being developed; however, their safety and efficacy are still being evaluated. Therefore, there is an urgent need to develop control measures to prevent or limit future Ebola virus outbreaks.Previously, we developed a replication-defective Ebola virus that lacks the coding region for the essential viral transcription activator VP30 (Ebola ΔVP30 virus). Here, we evaluated the vaccine efficacy of Ebola ΔVP30 virus in a non-human primate model and describe our collaborative Ebola project in Sierra Leone.

  19. [Effects of reforestation on tree pollen sensitization in inhabitants of Nuevo Leon, Mexico].

    Science.gov (United States)

    Palma-Gómez, Samuel; González-Díaz, Sandra Nora; Arias-Cruz, Alfredo; Macías-Weinmann, Alejandra; Amaro-Vivian, Laura Elizabeth; Pérez-Vanzzini, Rafael; Gutiérrez-Mujica, José Julio; Yong-Rodríguez, Adrián

    2014-01-01

    Climate change has implications for health, ecology and society. Urban green areas are a key element in the planning of cities, promoting citizen interaction with the environment, as well as health. Lack of planning and design of these areas as well as the selection of ornamental trees can be a trigger of pollen allergy in the surrounding population. Reforestation is among the programs implemented by the government that have an impact on allergy. Environmental reforestation programs do not take into account the allergenic potential of some species. In the last 4 years, the government of Nuevo Leon, Mexico, has planted nearly 18,000 Quercus species trees, in addition to an unknown number of Fraxinus species trees that are listed as tree species with high pollen production. To identify changes in tree pollen sensitization, based on environmental reforestation programs. A retrospective and descriptive study was done in which positive skin prick tests to pollen from trees in the interval of 2010-2014 were analyzed, correlating between tree species used for reforestation and increased sensitivity to the former. A statistically significant increase in pollen sensitization to species with which Nuevo Leon was reforested was found, along with a decrease in sensitization to the species that were not reforested. Reforestation contributes to some extent to the change in the pattern of positive skin tests and may result in more frequent exacerbations of respiratory diseases. It is an activity that should always be regulated and assisted by experts in the according field.

  20. Assessing biodiversity in Nuevo Leon, Mexico: Are nature reserves the answer?

    Science.gov (United States)

    Cantu, C.; Wright, R.G.; Scott, J.M.; Strand, Espen

    2004-01-01

    The Mexican state of Nuevo Leon, located in the northeastern portion of the country, currently has 26 state and three federal nature reserves covering approximately 4.5% of its land area. These reserves were established for a variety of reasons not necessarily related to conservation purposes. In 2000 in response to a growing concern about the lack of organized conservation reserve planning to protect the important biological and physical features of Mexico, the Mexican Commission for Knowledge and Use of Biodiversity proposed 12 new terrestrial reserves for Nuevo Leon. The new reserves, if established, would increase the proportion of protected lands in the state to almost 24% of the state's land area. We compiled a Geographic Information System (GIS) analysis using digital thematic maps of physical and ecological features to examine how well the existing and proposed reserves incorporated the major biological and physical features of the state. The existing reserves are located primarily in regions with elevations > 1,000-1,500 m, on less productive soils, and are dominated by pine and oak forest cover types. As a result, the state's dominant biotic region - low elevation coastal plain with xeric scrub vegetation - is disproportionately under represented in the current reserve system. The new reserves would expand the protection of biophysical resources throughout the state. However, the inclusion of important resources in the low elevation coastal lands would still be limited.

  1. Factors Underlying Ebola Virus Infection Among Health Workers, Kenema, Sierra Leone, 2014-2015.

    Science.gov (United States)

    Senga, Mikiko; Pringle, Kimberly; Ramsay, Andrew; Brett-Major, David M; Fowler, Robert A; French, Issa; Vandi, Mohamed; Sellu, Josephine; Pratt, Christian; Saidu, Josephine; Shindo, Nahoko; Bausch, Daniel G

    2016-08-15

    Ebola virus disease (EVD) in health workers (HWs) has been a major challenge during the 2014-2015 outbreak. We examined factors associated with Ebola virus exposure and mortality in HWs in Kenema District, Sierra Leone. We analyzed data from the Sierra Leone National Viral Hemorrhagic Fever Database, contact tracing records, Kenema Government Hospital (KGH) staff and Ebola Treatment Unit (ETU) rosters, and burial logs. From May 2014 through January 2015, 600 cases of EVD originated in Kenema District, including 92 (15%) HWs, 66 (72%) of whom worked at KGH. Among KGH medical staff and international volunteers, 18 of 62 (29%) who worked in the ETU developed EVD, compared with 48 of 83 (58%) who worked elsewhere in the hospital. Thirteen percent of HWs with EVD reported contact with EVD patients, while 27% reported contact with other infected HWs. The number of HW EVD cases at KGH declined roughly 1 month after implementation of a new triage system at KGH and the opening of a second ETU within the district. The case fatality ratio for HWs and non-HWs with EVD was 69% and 74%, respectively. The cluster of HW EVD cases in Kenema District is one of the largest ever reported. Most HWs with EVD had potential virus exposure both inside and outside of hospitals. Prevention measures for HWs must address a spectrum of infection risks in both formal and informal care settings as well as in the community. © 2016 World Health Organization; licensee Oxford Journals.

  2. Transmission network of the 2014-2015 Ebola epidemic in Sierra Leone.

    Science.gov (United States)

    Yang, Wan; Zhang, Wenyi; Kargbo, David; Yang, Ruifu; Chen, Yong; Chen, Zeliang; Kamara, Abdul; Kargbo, Brima; Kandula, Sasikiran; Karspeck, Alicia; Liu, Chao; Shaman, Jeffrey

    2015-11-06

    Understanding the growth and spatial expansion of (re)emerging infectious disease outbreaks, such as Ebola and avian influenza, is critical for the effective planning of control measures; however, such efforts are often compromised by data insufficiencies and observational errors. Here, we develop a spatial-temporal inference methodology using a modified network model in conjunction with the ensemble adjustment Kalman filter, a Bayesian inference method equipped to handle observational errors. The combined method is capable of revealing the spatial-temporal progression of infectious disease, while requiring only limited, readily compiled data. We use this method to reconstruct the transmission network of the 2014-2015 Ebola epidemic in Sierra Leone and identify source and sink regions. Our inference suggests that, in Sierra Leone, transmission within the network introduced Ebola to neighbouring districts and initiated self-sustaining local epidemics; two of the more populous and connected districts, Kenema and Port Loko, facilitated two independent transmission pathways. Epidemic intensity differed by district, was highly correlated with population size (r = 0.76, p = 0.0015) and a critical window of opportunity for containing local Ebola epidemics at the source (ca one month) existed. This novel methodology can be used to help identify and contain the spatial expansion of future (re)emerging infectious disease outbreaks. © 2015 The Author(s).

  3. Study of the Wall Paintings of the Cenador Del Leon in the Real Alcazar of Seville

    Science.gov (United States)

    Robador, Maria Dolores; Mancera, Inmaculada; Perez-Maqueda, Rafael; Albardonedo, Antonio

    2017-10-01

    The paintings on the walls of the Cenador del Leon located in the gardens of the Real Alcazar in Seville next to the Pabellon de Carlos V in the Jardin Ingles area have been studied. The components of the wall paintings cross-sections, which were prepared using small samples taken from the walls of Cenador del Leon, were characterized using infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) analysis. The cross-sections of the collected samples indicated that the paint layer is well adhered to the preparation layer without any discontinuity, and only one carbonation layer exists at the top of the sequence of layers. These data suggest that the paint was applied on a fresco surface, and therefore, the adopted technique was fresco. Based on the different elements detected by EDX analysis of the cross-sections, the detected pigments included iron oxides accompanied by clay minerals (or earths) in the red pink, golden yellow and yellow colours, blue smelt for the blue colour and basic copper chloride (atacamite) for the green colour. In one sample, the particles were composed of Ba and S from barium sulphate and Ti and O from rutile titanium oxide due to a modern pigment.

  4. Handling postpartum haemorrhage- obstetrics between tradition and modernity in post-war Sierra Leone.

    Science.gov (United States)

    Bräuer, Miriam Dorothea; Antón, Jorge; George, Peter Matthew; Kuntner, Liselotte; Wacker, Jürgen

    2015-04-01

    How traditional birth attendants (TBAs) in post-war Sierra Leone explain, handle and prevent postpartum haemorrhage (PPH) and their potential role in a better management of PPH to reduce maternal mortality in this low resource setting. Semi-quantitative interviews about knowledge and measures in PPH and participant observation with 140 Sierra Leonean birth attendants, divided in three groups: (A) TBAs who never attended any official training course (n = 82); (B) TBAs who attended at least one official training course (n = 48); and (C) officially trained birth attendants (n = 10). There are several observable gaps in the knowledge of TBAs about PPH compared to modern obstetrics, however similar procedures exist. Herbal medicine is applied; metaphysical convictions about PPH remain present. Training courses show an impact. Officially trained birth attendants demonstrate knowledge deficiencies and lack resources and infrastructure to manage PPH adequately. Morbidity and mortality of PPH in Sierra Leone is related to several factors and not solely to the ignorance of TBAs. TBAs still play an important role for many women there. Hence improvement of the formal health sector should be combined with life-saving programmes integrating TBAs in the care for the pregnant, delivering and breastfeeding mothers. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  5. Marginalization of girl mothers during reintegration from armed groups in Sierra Leone.

    Science.gov (United States)

    Burman, M E; McKay, S

    2007-12-01

    Although the widespread presence of girls who participate in fighting forces is increasingly recognized, they remain a highly marginalized group globally, receiving little attention either during or after armed conflict. This is especially true for "girl mothers," girls who return to communities with children born while members of fighting forces. The concept of marginalization (Hall et al. 1994) is used to examine what happens to girl soldiers, especially girl mothers, in the aftermath of armed conflict when they seek to reintegrate back into their communities. This analysis, as part of a larger study of reintegration of girl mothers, is based on field work with girls who were in fighting forces in northwest Sierra Leone, especially those who returned with children. The type and level of marginalization these girls experience is consistent with the conceptualization of marginalization; however, they lack voice and experience shame and vulnerability. Moreover, economics were fundamentally related to their marginalization. The girls' access to resources was significantly constrained because the area was heavily impacted by the war and because of widespread poverty throughout Sierra Leone. The findings raise important questions about marginalization of girls affected by war. Girls and girl mothers experience an extremely high level of marginalization; however, some aspects are not consistent with the original conceptualization of marginalization. Theory development in nursing needs to incorporate multiple voices, especially those of the very marginalized and be done in such a manner that benefits and empowers.

  6. Containing Ebola: A Test for Post-Conflict Security Sector Reform in Sierra Leone

    Directory of Open Access Journals (Sweden)

    Cathy Haenlein

    2015-07-01

    Full Text Available Ebola has provided the greatest test of the Sierra Leonean security sector – and, in turn, of the UK-led reforms of the past ten-to-fifteen years. The performance of the country's security forces at the height of the crisis suggests that there are sound structures in place; however, Ebola has shown that the Government of Sierra Leone's national security architecture still lacks maturity in responding to such a scenario. Drawing on first-hand interviews with advisers on the ground, this article explores the Sierra Leone government’s response to the Ebola crisis and the performance of the security sector so far, within the wider context of UK-led security-sector reform (SSR since the end of the civil war. In doing so, it highlights a number of lessons to have emerged from the crisis, exploring what these reveal about the nature of the reforms implemented since the end of the country's civil war. In turn, it explores what these suggest for future SSR, which continues to be a core component of the UK’s approach to development and overseas capacity-building.

  7. Effect of Sulfate in Sand on Some Mechanical Properties of Nano Metakaolin Normal Concrete

    Directory of Open Access Journals (Sweden)

    Zainab Hashim Abbas Alsallami

    2016-03-01

    Full Text Available This study aims to obtain the influence of adding Nano metakaolin on some mechanical properties of hardened concrete. Three levels of SO3 in sand were investigated, these levels were (0.27 (reference SO3, 0.5 and 1% by weight of fine aggregate. One level of Nano metakaolin replacements (1 % by weight of cement were used in this work. Nano metakaolin and SO3 contents were the only variables among the mixtures. Sulfates had its detrimental effect on properties of concrete. The presence of Nano metakaolin in normal concrete (NC mixes played a vital role in reducing the deterioration due to sulfates action. The experimental results show that there is an optimum gypsum content in sand (SO3 = 0.5% by weight of fine aggregate which gives the highest results in compressive strength, splitting strength and modulus of elasticity of NC. As gypsum content increases beyond this limit, the above mechanical properties will be decreased

  8. Advance, Retreat, and Halt of Abrupt Gravel-Sand Transitions in Alluvial Rivers

    Science.gov (United States)

    Blom, Astrid; Chavarrías, Víctor; Ferguson, Robert I.; Viparelli, Enrica

    2017-10-01

    Downstream fining of bed sediment in alluvial rivers is usually gradual, but often an abrupt decrease in characteristic grain size occurs from about 10 to 1 mm, i.e., a gravel-sand transition (GST) or gravel front. Here we present an analytical model of GST migration that explicitly accounts for gravel and sand transport and deposition in the gravel reach, sea level change, subsidence, and delta progradation. The model shows that even a limited gravel supply to a sand bed reach induces progradation of a gravel wedge and predicts the circumstances required for the gravel front to advance, retreat, and halt. Predicted modern GST migration rates agree well with measured data at Allt Dubhaig and the Fraser River, and the model qualitatively captures the behavior of other documented gravel fronts. The analysis shows that sea level change, subsidence, and delta progradation have a significant impact on the GST position in lowland rivers.

  9. Reviews of the geological and mining research conducted by the IGME in Leon, Zamora and Salamanca. Sintesis de las investigaciones geologicas-mineras realizadas por el IGME en Leon, Zamora y Salamanca

    Energy Technology Data Exchange (ETDEWEB)

    1980-01-01

    This paper comprises a review of the geological and mining research carried out by the Spanish Geological and Mining Institute in the provinces of Leon, Zamora and Salamanca. The review includes tables of the various coalfields showing production and productivity figures in the coal mines. (In Spanish)

  10. Fine target of deuterium

    International Nuclear Information System (INIS)

    Diaz Diaz, J.; Granados Gonzalez, C. E.; Gutierrez Bernal, R.

    1959-01-01

    A fine target of deuterium on a tantalum plate by the absorption method is obtained. In order to obtain the de gasification temperature an induction generator of high frequency is used and the deuterium pass is regulated by means of a palladium valve. Two vacuum measures are available, one to measure the high vacuum in the de gasification process of the tantalum plate and the other, for low vacuum, to measure the deuterium inlet in the installation and the deuterium pressure change in the installation after the absorption in the tantalum plate. A target of 48 μ gr/cm 2 thick is obtained. (Author) 1 refs

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

    Science.gov (United States)

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

    2013-09-01

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

  12. The Biogas from bio-energy electrical power plant of Nuevo Leon; Central electrica de biogas de bioenergia de Nuevo Leon

    Energy Technology Data Exchange (ETDEWEB)

    Arvizu F, Jose L [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico); Saldana M, Jaime L [Sistemas de Energia Internacional S.A. de C.V. (Mexico)

    2005-07-01

    The biogas from bio-energy electrical power plant of Nuevo Leon represents, in all the national territory, the first experience on the advantage of biogas emitted by the sanitary landfills for the generation of electrical energy. Therefore, one of the specific objectives of this paper is the one of diffusion and reproduction of the same one in other cities of Mexico and Latin America. The project is framed within the world-wide policies on the control of emissions for the reduction of the greenhouse effect gases (GEG) and its impact in the global climatic change. The gas emitted by the trash sanitary landfills, commonly known as biogas, is a gas mixture derived from the decomposition of the organic matter of the municipal trash by microorganisms in anaerobic conditions. Biogas generated in the sanitary landfills has a methane content of 55% and a 35% of carbon dioxide. The balance 10% is made up of water steam, hydrogen, nitrogen, oxygen, hydrogen sulfur and other gases in minimum amounts. [Spanish] La Central Electrica de Biogas de Bioenergia de Nuevo Leon representa, en todo el territorio nacional, la primera experiencia sobre el aprovechamiento del biogas emitido por los rellenos sanitarios para la generacion de energia electrica. Por esta razon, uno de los objetivos especificos de este trabajo es la de difusion y reproduccion del mismo en otras ciudades de Mexico y Latinoamerica. El proyecto esta enmarcado dentro de las politicas mundiales sobre el control de emisiones para la reduccion de los gases de efecto invernadero (GEI) y su impacto en el cambio climatico global. El gas emitido por la basura dispuesta en los rellenos sanitarios, comunmente conocido como biogas, es una mezcla de gases derivado de la descompensacion de la materia organica de la basura municipal por microorganismos en condiciones anaerobias. El biogas generado en los rellenos sanitarios tiene un contenido de metano del 55% y un 35% de bioxido de carbono. El 10% restante se compone de vapor

  13. Additive surface complexation modeling of uranium(VI) adsorption onto quartz-sand dominated sediments.

    Science.gov (United States)

    Dong, Wenming; Wan, Jiamin

    2014-06-17

    Many aquifers contaminated by U(VI)-containing acidic plumes are composed predominantly of quartz-sand sediments. The F-Area of the Savannah River Site (SRS) in South Carolina (USA) is an example. To predict U(VI) mobility and natural attenuation, we conducted U(VI) adsorption experiments using the F-Area plume sediments and reference quartz, goethite, and kaolinite. The sediments are composed of ∼96% quartz-sand and 3-4% fine fractions of kaolinite and goethite. We developed a new humic acid adsorption method for determining the relative surface area abundances of goethite and kaolinite in the fine fractions. This method is expected to be applicable to many other binary mineral pairs, and allows successful application of the component additivity (CA) approach based surface complexation modeling (SCM) at the SRS F-Area and other similar aquifers. Our experimental results indicate that quartz has stronger U(VI) adsorption ability per unit surface area than goethite and kaolinite at pH ≤ 4.0. Our modeling results indicate that the binary (goethite/kaolinite) CA-SCM under-predicts U(VI) adsorption to the quartz-sand dominated sediments at pH ≤ 4.0. The new ternary (quartz/goethite/kaolinite) CA-SCM provides excellent predictions. The contributions of quartz-sand, kaolinite, and goethite to U(VI) adsorption and the potential influences of dissolved Al, Si, and Fe are also discussed.

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

    Science.gov (United States)

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

    2015-04-01

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

  15. Examining Internet Usage Demographic Differences and the Relationship between Internet Usage and Business Outcomes in Sierra Leone

    Science.gov (United States)

    Kamara, Mohamed K.

    2013-01-01

    This study utilized the unified theory of acceptance and use of technology (UTAUT) to determine Internet users' perceptions and behavioral intentions to accept Wi-Fi technology deployment in Sierra Leone. The study sought to investigate (a) the Internet usage rates before and after Wi-Fi adaption in Freetown; (b) differences in Internet usage…

  16. Prevalence and Risk Factors for Human Immunodeficiency Virus (HIV) and Syphilis Infections Among Military Personnel in Sierra Leone

    Science.gov (United States)

    2017-03-01

    2017 Bentham Science Publishers Prevalence and Risk Factors for Human Immunodeficiency Virus ( HIV ) and Syphilis Infections Among Military Personnel...immunodeficiency virus ( HIV ) and syphilis, potentially im- pact the Republic of Sierra Leone Armed Forces (RSLAF) by reducing their effectiveness and...Mosala T. Divergent spatial patterns in the prevalence of the human immunodeficiency virus ( HIV ) and syphilis in South African pregnant women. Geospat

  17. Food Deserts in Leon County, FL: Disparate Distribution of Supplemental Nutrition Assistance Program-Accepting Stores by Neighborhood Characteristics

    Science.gov (United States)

    Rigby, Samantha; Leone, Angela F.; Kim, Hwahwan; Betterley, Connie; Johnson, Mary Ann; Kurtz, Hilda; Lee, Jung Sun

    2012-01-01

    Objective: Examine whether neighborhood characteristics of racial composition, income, and rurality were related to distribution of Supplemental Nutrition Assistance Program (SNAP)-accepting stores in Leon County, Florida. Design: Cross-sectional; neighborhood and food store data collected in 2008. Setting and Participants: Forty-eight census…

  18. Learning Styles and Attitudes toward Online Education in Four Universities in the State of Nuevo Leon, Mexico

    Science.gov (United States)

    Martinez de Monarrez, Patricia; Korniejczuk, Victor

    2013-01-01

    The purpose of this research was to find the relation-ship between the predominant learning styles among university online students and their attitude toward online education. Data were collected from 385 students enrolled in undergraduate and graduate programs from four universities in the state of Nuevo Leon, Mexico. Significant effects of…

  19. The Effect of Variation of Molarity of Alkali Activator and Fine Aggregate Content on the Compressive Strength of the Fly Ash: Palm Oil Fuel Ash Based Geopolymer Mortar

    Directory of Open Access Journals (Sweden)

    Iftekhair Ibnul Bashar

    2014-01-01

    Full Text Available The effect of molarity of alkali activator, manufactured sand (M-sand, and quarry dust (QD on the compressive strength of palm oil fuel ash (POFA and fly ash (FA based geopolymer mortar was investigated and reported. The variable investigated includes the quantities of replacement levels of M-sand, QD, and conventional mining sand (N-sand in two concentrated alkaline solutions; the contents of alkaline solution, water, POFA/FA ratio, and curing condition remained constant. The results show that an average of 76% of the 28-day compressive strength was found at the age of 3 days. The rate of strength development from 3 to 7 days was found between 12 and 16% and it was found much less beyond this period. The addition of 100% M-sand and QD shows insignificant strength reduction compared to mixtures with 100% N-sand. The particle angularity and texture of fine aggregates played a significant role in the strength development due to the filling and packing ability. The rough texture and surface of QD enables stronger bond between the paste and the fine aggregate. The concentration of alkaline solution increased the reaction rate and thus enhanced the development of early age strength. The use of M-sand and QD in the development of geopolymer concrete is recommended as the strength variation between these waste materials and conventional sand is not high.

  20. Provenance and tectonic settings of sands from Puerto Peñasco, Desemboque and Bahia Kino beaches, Gulf of California, Sonora, México

    Science.gov (United States)

    Madhavaraju, J.; Tom, Milu; Lee, Yong IL; Balaram, V.; Ramasamy, S.; Carranza-Edwards, A.; Ramachandran, A.

    2016-11-01

    Textural, heavy minerals and geochemical (major, trace and rare earth elements) studies were undertaken on the sands from Puerto Peñasco, Desemboque and Bahia Kino beaches to determine the provenance and tectonic settings. Puerto Peñasco and Bahia Kino sands are coarse grained to fine grained, while Desemboque sands are fine grained. Geochemically, these sands are classified as arkose. The sands are depleted in most of the trace elements relative to upper continental crust (UCC), except for few trace elements (Sr, Rb and Ba), which are slightly enriched. High ΣREE content are observed in the Desemboque sands (94.43 ± 6.9) than in the Puerto Peñasco and Bahia Kino sands (51.58 ± 17.06; 72.38 ± 9.27; respectively). The chemical index of alteration (CIA) values of Puerto Peñasco, Desemboque and Bahia Kino sands (PP: 42 to 50; DE: 48 to 50; BK: 44 to 50: respectively) indicate the low intensity of chemical weathering in the source rocks. The tectonic discriminant-function-based multidimensional diagram shows arc and rift settings for Puerto Peñasco sands whereas rift setting for both Desemboque and Bahia Kino sands. The heavy mineral assemblage, immobile trace elements, REE patterns, elemental ratios such Eu/Eu*, (La/Lu)cn, La/Sc, Th/Sc, La/Co, Th/Co, and Cr/Th, various bivariate and ternary plots indicate the contribution of sediments from felsic composition. This interpretation is supported by the comparison of REE patterns of the Puerto Peñasco, Desemboque and Bahia Kino sands with the potential source rocks exposed nearby the study areas.

  1. The Sands of the Bagnold Dunes, Mars and Volatiles in Mars Soils

    Science.gov (United States)

    Ehlmann, B. L.; Edgett, K. S.; Sutter, B.; Achilles, C.; Litvak, M. L.; Lapotre, M. G. A.; Sullivan, R. J., Jr.; Fraeman, A. A.; Arvidson, R. E.; Blake, D. F.; Bridges, N. T.; Conrad, P. G.; Cousin, A.; Downs, R. T.; Gabriel, T. S. J.; Gellert, R.; Hamilton, V. E.; Hardgrove, C. J.; Johnson, J. R.; Kuhn, S.; Mahaffy, P. R.; Maurice, S.; Meslin, P. Y.; McHenry, M.; Ming, D. W.; Minitti, M. E.; Morookian, J.; Morris, R. V.; O'Connell-Cooper, C.; Pinet, P. C.; Rowland, S. K.; Schröder, S.; Siebach, K. L.; Stein, N.; Thompson, L. M.; Vaniman, D.; Vasavada, A. R.; Wellington, D. F.; Wiens, R. C.; Yen, A.

    2017-12-01

    The Mars Science Laboratory Curiosity rover performed coordinated measurements to examine the textures and compositions of aeolian sands in an active portion of the Bagnold dune field. The composition and grain size information were reviewed in Ehlmann et al. [2017, JGR-Planets and papers referenced therein]. The Bagnold sands are rounded to subrounded, very fine to medium sized ( 45-500 μm) with ≥6 distinct grain colors. In contrast to sands examined by Curiosity in a dust-covered, inactive bedform called Rocknest and soils at other landing sites, Bagnold sands are darker, less red, better sorted, have fewer silt-sized or smaller grains, and show no evidence for cohesion. Nevertheless, Bagnold mineralogy and Rocknest mineralogy are similar with plagioclase, olivine, and pyroxenes in similar proportions comprising >90% of crystalline phases, along with a substantial amorphous component (35% ± 15%) [Achilles et al., 2017]. Like Rocknest, release of CO2 and NO is higher than Gale rocks, implying enrichment in the carrier phases of these volatiles [Sutter et al., 2017]. Yet Bagnold and Rocknest bulk chemistries differ. Bagnold sands are Si-enriched relative to other soils at Gale crater [Cousin et al., 2017; O'Connell-Cooper et al., 2017], and H2O, S, and Cl are lower relative to all previously measured Martian soils and most Gale crater rocks. Mg, Ni, Fe, and Mn are enriched in the coarse-sieved fraction of Bagnold sands [Cousin et al., 2017; O'Connell-Cooper et al., 2017], corroborated by visible/near-infrared spectra that suggest enrichment of olivine [Johnson et al., 2017]. Collectively, patterns in major element chemistry and volatile release data indicate two distinctive volatile reservoirs in Martian soils: (1) amorphous components in the sand-sized fraction (represented by Bagnold) that are Si-enriched, hydroxylated alteration products and/or impact or volcanic glasses and (2) amorphous components in the fine fraction (<40 μm; represented by Rocknest and

  2. Sand Dunes in Kaiser Crater

    Science.gov (United States)

    2002-01-01

    Full size (780 KBytes) This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) high resolution image shows a field of dark sand dunes on the floor of Kaiser Crater in southeastern Noachis Terra. The steepest slopes on each dune, the slip faces, point toward the east, indicating that the strongest winds that blow across the floor of Kaiser move sand in this direction. Wind features of three different scales are visible in this image: the largest (the dunes) are moving across a hard surface (light tone) that is itself partially covered by large ripples. These large ripples appear not to be moving--the dunes are burying some and revealing others. Another type of ripple pattern is seen on the margins of the dunes and where dunes coalesce. They are smaller (both in their height and in their separation) than the large ripples. These are probably coarse sediments that are moving with the dunes. This picture covers an area approximately 3 km (1.9 mi) across and is illuminated from the upper left.

  3. The effect of limited availability of N or water on C allocation to fine roots and annual fine root turnover in Alnus incana and Salix viminalis.

    Science.gov (United States)

    Rytter, Rose-Marie

    2013-09-01

    The effect of limited nitrogen (N) or water availability on fine root growth and turnover was examined in two deciduous species, Alnus incana L. and Salix viminalis L., grown under three different regimes: (i) supply of N and water in amounts which would not hamper growth, (ii) limited N supply and (iii) limited water supply. Plants were grown outdoors during three seasons in covered and buried lysimeters placed in a stand structure and filled with quartz sand. Computer-controlled irrigation and fertilization were supplied through drip tubes. Production and turnover of fine roots were estimated by combining minirhizotron observations and core sampling, or by sequential core sampling. Annual turnover rates of fine roots root production (roots 1-2 mm. Proportionally more C was allocated to fine roots (≤2 mm) in N or water-limited Salix; 2.7 and 2.3 times the allocation to fine roots in the unlimited regime, respectively. Estimated input to soil organic carbon increased by ca. 20% at N limitation in Salix. However, future studies on fine root decomposition under various environmental conditions are required. Fine root growth responses to N or water limitation were less pronounced in Alnus, thus indicating species differences caused by N-fixing capacity and slower initial growth in Alnus, or higher fine root plasticity in Salix. A similar seasonal growth pattern across species and treatments suggested the influence of outer stimuli, such as temperature and light.

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

    Energy Technology Data Exchange (ETDEWEB)

    Schreckengost, D.; Arnold, D.

    1984-09-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Seol, Yongkoo; Kneafsey, Timothy J.

    2009-06-01

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

  6. Single motherhood and neonatal and infant mortality in Sierra Leone, Burkina Faso and Burundi.

    Science.gov (United States)

    Izugbara, C

    2016-06-01

    Childhood mortality is a stubborn problem and remains highest in Sub-Saharan Africa (SSA). Existing research on childhood mortality in SSA indicate that most of the childhood deaths are from preventable causes such as diarrhoea, pneumonia, measles, malaria, HIV and underlying malnutrition, acute respiratory infections, whooping cough, tuberculosis, bronchopneumonia, dirty feeding bottles and utensils, inadequate disposal of household refuse and poor storage of drinking water. However, insufficient attention has been given to maternal marital status and childhood mortality relationships. Understanding the implications of maternal marital status for childhood mortality can add to our knowledge of the correlates of neonatal and infant mortality and furnish insights to support the design and delivery of interventions to address the problem. To document and examine the extent to which the association between neonatal and infant mortality varies between single and ever-married mothers in Sierra Leone, Burkina Faso, and Burundi. A single mother is defined in this study as a woman who has either lived with a partner, married before, widowed, separated during the survey periods and has given at least one life birth. Ever-married woman is woman who has been married at least once in their lives although their current marital status may not be married. Data for this study were drawn from the latest Demographic and Health Surveys (DHS) in Burkina Faso, Sierra Leone and Burundi. The selected datasets came from 2010 Burkina Faso DHS (BFDHS), 2008 Sierra Leone DHS (SLDHS) and 2010 Burundi DHS (EDSB II). The relevant data for this study (women age 15-49 years who had at least one live birth within the five years preceding the survey) were extracted from the whole dataset of each country (Burkinabe (n = 17,087), Sierra Leonean (n = 7374) and Burundian (n = 9389). Univariate and multivariate statistical analyses were used to assess the association between neonatal and infant

  7. Potential Exposure to Ebola Virus from Body Fluids due to Ambulance Compartment Permeability in Sierra Leone.

    Science.gov (United States)

    Casey, Megan L; Nguyen, Duong T; Idriss, Barrie; Bennett, Sarah; Dunn, Angela; Martin, Stephen

    2015-12-01

    Prehospital care, including patient transport, is integral in the patient care process during the Ebola response. Transporting ill persons from the community to Ebola care facilities can stop community spread. Vehicles used for patient transport in infectious disease outbreaks should be evaluated for adequate infection prevention and control. An ambulance driver in Sierra Leone attributed his Ebola infection to exposure to body fluids that leaked from the patient compartment to the driver cabin of the ambulance. A convenience sample of 14 vehicles used to transport patients with suspected or confirmed Ebola in Sierra Leone were assessed. The walls separating the patient compartment and driver cabin in these vehicles were evaluated for structural integrity and potential pathways for body fluid leakage. Ambulance drivers and other staff were asked to describe their cleaning and decontamination practices. Ambulance construction and design standards from the National Fire Protection Association, US General Services Administration, and European Committee on Standardization (CEN) were reviewed. Many vehicles used by ambulance staff in Sierra Leone were not traditional ambulances, but were pick-up trucks or sport-utility vehicles that had been assembled or modified for patient transport. The wall separating the patient compartment and driver cabin in many vehicles did not have a waterproof seal around the edges. Staff responsible for cleaning and disinfection did not thoroughly clean bulk body fluids with disposable towels before disinfection of the patient compartment. Pressure from chlorine sprayers used in the decontamination process may have pushed body fluids from the patient compartment into the driver cabin through gaps around the wall. Ambulance design standards do not require a waterproof seal between the patient compartment and driver cabin. Sealing the wall by tightening or replacing existing bolts is recommended, followed by caulking of all seams with a

  8. Granulation of fine powder

    Science.gov (United States)

    Chen, Ching-Fong

    2016-08-09

    A mixture of fine powder including thorium oxide was converted to granulated powder by forming a first-green-body and heat treating the first-green-body at a high temperature to strengthen the first-green-body followed by granulation by crushing or milling the heat-treated first-green-body. The granulated powder was achieved by screening through a combination of sieves to achieve the desired granule size distribution. The granulated powder relies on the thermal bonding to maintain its shape and structure. The granulated powder contains no organic binder and can be stored in a radioactive or other extreme environment. The granulated powder was pressed and sintered to form a dense compact with a higher density and more uniform pore size distribution.

  9. Radiology and fine art.

    Science.gov (United States)

    Marinković, Slobodan; Stošić-Opinćal, Tatjana; Tomić, Oliver

    2012-07-01

    The radiologic aesthetics of some body parts and internal organs have inspired certain artists to create specific works of art. Our aim was to describe the link between radiology and fine art. We explored 13,625 artworks in the literature produced by 2049 artists and found several thousand photographs in an online image search. The examination revealed 271 radiologic artworks (1.99%) created by 59 artists (2.88%) who mainly applied radiography, sonography, CT, and MRI. Some authors produced radiologic artistic photographs, and others used radiologic images to create artful compositions, specific sculptures, or digital works. Many radiologic artworks have symbolic, metaphoric, or conceptual connotations. Radiology is clearly becoming an original and important field of modern art.

  10. Experimental Investigation of the Effect of Manufactured Sand and Lightweight Sand on the Properties of Fresh and Hardened Self-Compacting Lightweight Concretes.

    Science.gov (United States)

    Zhu, Yiyun; Cui, Hongzhi; Tang, Waiching

    2016-08-29

    Self-compacting lightweight concrete (SCLC) is a promising construction material for building applications, but most SCLCs today are made with river sand (RS). There is an increasing demand for environmental protection, as well as materials with a high strength/density ratio. The manufactured sand (MS) and lightweight sand (LS) as fine aggregates in cement-based composite materials have been receiving more attention among researchers. However, there is not much information about the effects of MS and LS on the properties of the fresh and hardened SCLCs. In this paper, the properties of fresh and hardened SCLC made with MS and LS were investigated by a series of experiments. SCLCs made with RS served as the control in this study. The test results show that increasing the sand ratio (from 0.40-0.50) decreased the filling ability and led to an increased T 50 time, which is the time spent for the concrete to reach the 500 mm spread circle, for all of the fresh SCLCs. Although the passing ability of MS-SCLCs and LS-SCLCs is not as good as RS-SCLCs, their results are still within an acceptable range. The ratio of mechanical properties to density was found to increase with an increase of the sand ratio for all of the hardened SCLCs. MS-SCLCs presented the highest compressive strength among all of the SCLCs studied. Although the mean compressive strength of LS-SCLCs is lower than those of the other two SCLCs by 8%, their strength to density ratio is higher than others by 15%, and the ratio increases remarkably with the increase of the sand ratio. Permeability test results showed that the permeability coefficient of MS-SCLC is remarkably lower than that of LS-SCLC, but slightly higher than that of RS-SCLC.

  11. Water Use for Cultivation Management of Watermelon in Upland Field on Sand Dune

    Science.gov (United States)

    Hashimoto, Iwao; Senge, Masateru; Itou, Kengo; Maruyama, Toshisuke

    Early-maturing cultivation of watermelon in a plastic tunnel was invetigated in upland field on sand dune on the coast of the Japan Sea to find water use to control blowing sand and to transplant seedlings. This region has low precipitation, low humidity, and strong wind in March and April, when sand is readily blown in the field. Water is used to control blowing sand on days with precipitation below 5 mm, minimum humidity below the meteorological average in April, and maximum wind velocity above the meteorological average in April. For the rooting and growth of watermelon seedlings, soil temperature needs to be raised because it is low in April. Ridges are mulched with transparent, porous polyethylene films 10 or more days before transplanting the seedlings and irrigated with sprinklers on fine days for the thermal storage of solar energy. The stored heat steams the mulched ridges to raise soil temperature to 15°C or higher on the day of transplanting the seedlings. The total amount of irrigation water used for watermelon cultivation was 432.7 mm, of which 23.6 mm was for blowing sand control and 26.6 mm was for transplanting the seedlings. The combined amount, 50.2 mm, is 11.6% of the total amount of water used for cultivation management.

  12. Fuel options for oil sands

    International Nuclear Information System (INIS)

    Wise, T.

    2005-01-01

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

  13. Revised Soil Classification System for Coarse-Fine Mixtures

    KAUST Repository

    Park, Junghee

    2017-04-17

    Soil classification systems worldwide capture great physical insight and enable geotechnical engineers to anticipate the properties and behavior of soils by grouping them into similar response categories based on their index properties. Yet gravimetric analysis and data trends summarized from published papers reveal critical limitations in soil group boundaries adopted in current systems. In particular, current classification systems fail to capture the dominant role of fines on the mechanical and hydraulic properties of soils. A revised soil classification system (RSCS) for coarse-fine mixtures is proposed herein. Definitions of classification boundaries use low and high void ratios that gravel, sand, and fines may attain. This research adopts emax and emin for gravels and sands, and three distinctive void ratio values for fines: soft eF|10  kPa and stiff eF|1  MPa for mechanical response (at effective stress 10 kPa and 1 MPa, respectively), and viscous λ⋅eF|LL for fluid flow control, where λ=2log(LL−25) and eF|LL is the void ratio at the liquid limit. For classification purposes, these void ratios can be estimated from index properties such as particle shape, the coefficient of uniformity, and the liquid limit. Analytically computed and data-adjusted boundaries are soil-specific, in contrast with the Unified Soil Classification System (USCS). Threshold fractions for mechanical control and for flow control are quite distinct in the proposed system. Therefore, the RSCS uses a two-name nomenclature whereby the first letters identify the component(s) that controls mechanical properties, followed by a letter (shown in parenthesis) that identifies the component that controls fluid flow. Sample charts in this paper and a Microsoft Excel facilitate the implementation of this revised classification system.

  14. Microstructure Based Material-Sand Particulate Interactions and Assessment of Coatings for High Temperature Turbine Blades

    Science.gov (United States)

    Murugan, Muthuvel; Ghoshal, Anindya; Walock, Michael; Nieto, Andy; Bravo, Luis; Barnett, Blake; Pepi, Marc; Swab, Jeffrey; Pegg, Robert Tyler; Rowe, Chris; hide

    2017-01-01

    Gas turbine engines for military/commercial fixed-wing and rotary wing aircraft use thermal barrier coatings in the high-temperature sections of the engine for improved efficiency and power. The desire to further make improvements in gas turbine engine efficiency and high power-density is driving the research and development of thermal barrier coatings and the effort of improving their tolerance to fine foreign particulates that may be contained in the intake air. Both commercial and military aircraft engines often are required to operate over sandy regions such as in the Middle-East nations, as well as over volcanic zones. For rotorcraft gas turbine engines, the sand ingestion is adverse during take-off, hovering near ground, and landing conditions. Although, most of the rotorcraft gas turbine engines are fitted with inlet particle separators, they are not 100 percent efficient in filtering fine sand particles of size 75 microns or below. The presence of these fine solid particles in the working fluid medium has an adverse effect on the durability of turbine blade thermal barrier coatings and overall performance of the engine. Typical turbine blade damages include blade coating wear, sand glazing, Calcia-Magnesia-Alumina-Silicate (CMAS) attack, oxidation, plugged cooling holes, all of which can cause rapid performance deterioration including loss of aircraft. The objective of this research is to understand the fine particle interactions with typical ceramic coatings of turbine blades at the microstructure level. A finite-element based microstructure modeling and analysis has been performed to investigate particle-surface interactions, and restitution characteristics. Experimentally, a set of tailored thermal barrier coatings and surface treatments were down-selected through hot burner rig tests and then applied to first stage nozzle vanes of the Gas Generator Turbine of a typical rotorcraft gas turbine engine. Laser Doppler velocity measurements were performed

  15. Response to Oil Sands Products Assessment

    Science.gov (United States)

    2015-09-01

    Canada’s total proven reserves the third largest in the world, after Saudi Arabia’s conventional oil and Venezuela’s Orinoco oil sands. In 1967, the...largest in the world, after Saudi Arabia’s conventional oil and Venezuela’s Orinoco oil sands. (See Figure 2) Source: (National Academy of Science

  16. Understanding Colombian Amazonian white sand forests

    NARCIS (Netherlands)

    Peñuela-Mora, M.C.

    2014-01-01

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

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

    African Journals Online (AJOL)

    Seasonal fluctuations of phlebotomines sand fly populations (Diptera: Psychodidae) in the Moulay Yacoub province, centre Morocco: Effect of ecological factors. ... Sand flies were collected twice a month between April 2011 and March 2012, using sticky traps and CDC light traps. 3675 specimens were collected (78.3% ...

  18. Excerpt of the Interview with Mathew Sands

    Indian Academy of Sciences (India)

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

  19. Rheological analysis of fine-grained natural debris-flow material

    Science.gov (United States)

    Major, Jon J.; Pierson, Thomas C.; ,

    1990-01-01

    Experiments were conducted on large samples of fine-grained material (???2mm) from a natural debris flow using a wide-gap concentric-cylinder viscometer. The rheological behavior of this material is compatible with a Bingham model at shear rates in excess of 5 sec. At lesser shear rates, rheological behavior of the material deviates from the Bingham model, and when sand concentration of the slurry exceeds 20 percent by volume, particle interaction between sand grains dominates the mechanical behavior. Yield strength and plastic viscosity are extremely sensitive to sediment concentration.

  20. Education Programs in Post-Conflict Environments: a Review from Liberia, Sierra Leone, and South Africa

    Directory of Open Access Journals (Sweden)

    Hernando Barrios-Tao

    2016-12-01

    Full Text Available Education should be considered as one of the mechanisms for governments and nations to succeed in a post-conflict process. The purpose of this Review Article is twofold: to explain the importance of education in a post-conflict setting, and to describe a few strategies that post-conflict societies have implemented. In terms of research design, a multiple case study approach has been implemented. The paper reviews a unique topic with specific reference to education plans implemented in post-conflict societies such as Liberia, Sierra Leone, and South Africa. Each of them has experienced violent conflicts and has used education as a tool to succeed in their post-conflict process. In sum, there are several educational programs that involve children, young people, survivors, parents, teachers, and local communities as well as curriculums focused on teaching of cultural values and technical skills to improve the quality of life in a post-conflict setting.

  1. Collective Sexual Violence in Bosnia and Sierra Leone: A Comparative Case Study Analysis.

    Science.gov (United States)

    Ten Bensel, Tusty; Sample, Lisa L

    2017-08-01

    Social scientists have long studied the patterns, motivations, and recidivism rates of sexual offenders; however, the majority of prior research has examined rape, where victims are assaulted by a single offender in isolated events. Often overlooked are sexually violent assaults committed during armed conflicts, which often exhibit group-level sexual offending. This oversight could be a result of perceived notions that sexual violence during conflict is a rare or regrettable event; however, it has been documented consistently throughout history. The purpose of this study was to improve our understanding of sexual violence during war by comparing and contrasting preconflict characteristics, conflict framing, and justifications for sexual violence in the Bosnian and Sierra Leone armed conflicts. This greater understanding can then be used to identify factors that may contribute to the collectivization of sexual violence during war.

  2. EL UTILITARISMO DE JEREMY BENTHAM ¿FUNDAMENTO DE LA TEORÍA DE LEON WALRAS?

    Directory of Open Access Journals (Sweden)

    Aída-Sofía Rivera-Sotelo

    2011-12-01

    Full Text Available El presente texto cuestiona el utilitarismo de Jeremy Bentham como fundamento de la teoría marginalista walrasiana. La problemática se aborda a través de un análisis comparativo del pensamiento de Jeremy Bentham y de Leon Walras en tres áreas centrales: sus visiones de la sociedad y el objetivo social, sus aproximaciones teóricas y metodológicas en relación directa con sus respectivas teorías de la sociedad, y el lugar del principio de utilidad en el marco de las teorías generales de sociedad. El escrito contribuye a un debate vigente sobre los fundamentos filosóficos de la teoría de la elección racional y a deshomogenizar el pensamiento de los padres del marginalismo.

  3. Global health business: the production and performativity of statistics in Sierra Leone and Germany.

    Science.gov (United States)

    Erikson, Susan L

    2012-01-01

    The global push for health statistics and electronic digital health information systems is about more than tracking health incidence and prevalence. It is also experienced on the ground as means to develop and maintain particular norms of health business, knowledge, and decision- and profit-making that are not innocent. Statistics make possible audit and accountability logics that undergird the management of health at a distance and that are increasingly necessary to the business of health. Health statistics are inextricable from their social milieus, yet as business artifacts they operate as if they are freely formed, objectively originated, and accurate. This article explicates health statistics as cultural forms and shows how they have been produced and performed in two very different countries: Sierra Leone and Germany. In both familiar and surprising ways, this article shows how statistics and their pursuit organize and discipline human behavior, constitute subject positions, and reify existing relations of power.

  4. Strategic environmental assessment of hydrological and irrigation plans in Castilla y Leon, Spain

    Energy Technology Data Exchange (ETDEWEB)

    Hedo, D.; Bina, O. (Sociedad Espanola de Ornitologia/BirdLife International, Madrid (Spain))

    1999-05-01

    The study illustrates how strategic environmental assessment (SEA) can promote sustainable development plans. It defines and applies an SEA methodology to two draft plans: the hydrological plan for the Duero basin in Spain and the irrigation plan for the region of Castilla y Leon. Although prepared by national and regional authorities, respectively, both draft plans refer to the management and use of water as a resource for economic development and refer roughly to the same area. The SEA addresses the environmental, economic, and social impacts of the combined draft plans, using relevant indicators and objectives. The analysis shows that the proposals would lead to high financial costs and significant negative impacts on the environment for each job created; it develops and assesses a number of alternatives that would address these impacts. The results are used to define SEA procedures for the new Structural Funds period (2000--2006) and will provide a useful lesson for plans at all levels of government within Spain.

  5. The life and work of Leon Henkin essays on his contributions

    CERN Document Server

    Sain, Ildikó; Alonso, Enrique

    2014-01-01

    This is a comprehensive book on the life and works of Leon Henkin (1921–2006), an extraordinary scientist and excellent teacher whose writings became influential right from the beginning of his career with his doctoral thesis on “The completeness of formal systems” under the direction of Alonzo Church. Upon the invitation of Alfred Tarski, Henkin joined the Group in Logic and the Methodology of Science in the Department of Mathematics at the University of California Berkeley in 1953. He stayed with the group until his retirement in 1991. This edited volume includes both foundational material and a logic perspective. Algebraic logic, model theory, type theory, completeness theorems, philosophical and foundational studies are among the topics covered, as well as mathematical education. The work discusses Henkin’s intellectual development, his relation to his predecessors and contemporaries, and his impact on the recent development of mathematical logic. It offers a valuable reference work for researcher...

  6. Territorial identity and landscape. Evolution morphology of nuclei in Castilla y Leon

    International Nuclear Information System (INIS)

    Cortes Pedrosa, J.

    2015-01-01

    This paper aims to study the physical and socioeconomic transformations of rural settlements belonging to the Spanish region of Castile and Leon, throughout the second half of the 20th century. The evolution of urban form is analyzed, using a geographical information system (GIS) and calculating several shape metrics, and is then related to historical demographical data. The results are meant to show the effects of functional specialization, caused by the integration of rural regions in global economic hierarchies, on settlement structures and patterns. Gradual loss of the traditional features of Castilian villages, such as urban compactness and integration in the landscape, due to the disappearance or neglect of vernacular architecture and the construction of new industrial infrastructures, poses a risk for future place-based development policies. It is deemed necessary to preserve local identity and avoid destruction or degradation of the traditional heritage for revitalizing these territories. (Author)

  7. Processed bottom ash for replacing fine aggregate in making high-volume fly ash concrete

    Directory of Open Access Journals (Sweden)

    Antoni

    2017-01-01

    Full Text Available Bottom ash is a coal plant by-product that is abundant and underutilized. There is the potential use of bottom ash as a fine aggregate replacement in concrete mixtures; however, the problems of water absorption and uniformity of quality of the material need to be overcome first. In this study, bottom ash was treated by sieve separation and pounding to smaller particle size for use as a sand substitute. The physical and chemical characteristics of bottom ash were tested after treatment including water absorption, sieve analysis, and fineness modulus. Highvolume fly ash (HVFA mortar specimens were made and the compressive strength and flowability test using bottom ash after treatment are compared with that of the sand specimen. Low water to cementitious ratio was used to ensure higher strength from the cementitious paste and superplasticizer demand was determined for each treatment. The result showed that bottom ash can be used as fine aggregate replacement material. Sieve separation of the bottom ash could produce 75% of the compressive strength compared with the control sand specimen, whereas pounded bottom ash could have up to 96% of the compressive strength of the control specimen. A 28-day compressive strength of 45 MPa was achievable with 100% replacement of fine aggregate with bottom ash.

  8. Experimental assessment of the liquefaction resistance of calcareous biogenous sands

    Directory of Open Access Journals (Sweden)

    Sandoval Eimar

    2012-10-01

    Full Text Available

    ABSTRACT

    Liquefaction is a phenomenon in which soils, typically sands, suddenly loose a substantial amount of their shear strength and stiffness, this often triggered by large-magnitude earthquakes. Most liquefaction research has focused on silicate-based sands and not on other sand types, such as calcareous biogenous sands Calcareous sands are usually composed of skeletal or non-skeletal remains of marine organisms, with unique characteristics in terms of their mineralogy surface roughness, particle shape, crushability, and intraparticle porosity. The unique characteristics of calcareous sands suggest that their geotechnical engineering behaviour can be substantially different compared to that of terrigenous sands, including their behaviour under seismic loading, which have not been very well studied

    This paper presents the results of an experimental programme aimed at studying the cyclic liquefaction resistance of uncemented calcareous biogenous sands retrieved from south-western Puerto Rico Evaluation of liquefaction potential involved a comprehensive set of isotropically consolidated undrained cyclic triaxial tests on reconstituted samples of this calcareous sand. The programme also included tests on Ottawa terrigenous silica sand samples prepared and tested in similar conditions for comparison purposes.

    In general, the experimental results showed that Cabo Rojo calcareous sands had higher liquefaction resistance compared to Ottawa silica sands tested under similar conditions. Important differences between calcareous and silica sands regarding pore pressure generation characteristics and axial strain accumulation were also observed


  9. Pond 1 : closure of the first oil sands tailings pond

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, H.B.; Wells, P.S.; Cox, L. [Suncor Energy Inc., Fort McMurray, AB, (Canada)

    2010-07-01

    This paper described the evolution of reclamation goals and practices that followed the 40-year operating life and closure of an oil sands tailings pond in northeastern Alberta. Pond 1 and the associated containment dyke were first developed without any reclamation goals. The first reclamation practices evolved from a need to prevent erosion to the containment dyke. Reclamation practices developed from research and operational trials seeking to meet increasingly sophisticated reclamation goals, including species selection, propagation techniques, and pest control. The goal became to reclaim developed lands to viable ecosystems compatible with pre-development, changing the focus to the infilling and reclamation of the pond interior. To reduce the reclamation time frame, the Mature Fine Tailings were removed for treatment and replaced with sand beaches to create a trafficable surface and minimize environmental impacts. For reclaiming the pond surface, the landform design objectives were to create a geotechnically stable landscape, reduce the infiltration of precipitation into the beach, create a revegetated landscape to support wildlife and traditional land uses, and create a small wetland without affecting geotechnical stability. The reclamation soil cover design, wildlife enhancement features, wetland design, and revegetation prescriptions were described. In contrast to when the pond began operation, the pond closure was undertaken in a highly regulated environment with a substantial foundation of reclamation knowledge and clearly defined reclamation and end land-use goals. The pond was infilled in 2009, and surface landforming and revegetation were scheduled for completion by the fall 2010. 2 refs., 1 tab., 1 fig.

  10. Oil sands tailings technology : understanding the impact to reclamation

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-07-01

    This paper discussed tailings management techniques at oil sands mines and their effects on reclamation schedules and outcomes. The layer of mature fine tailings (MFT) that forms in tailings ponds does not settle within a reasonable time frame, requiring more and larger tailings ponds for storing MFT. Consolidated tailings (CT) technology was developed to accelerate the consolidation of MFT, although the process nonetheless takes decades. CT is produced from mixing tailings sand, gypsum, and MFT to create a mixture that will consolidate more quickly and release water. However, CT production is tied to the extraction process, making it applicable only when the plant is operational, and a precise recipe and accurate injection are required for CT to work. In tailings reduction operations (TRO), a new approach to tailings management, MFT is mixed with a polymer flocculant, deposited in thin layers, and allowed to dry. TRO has a significant advantage over CT in that the latter takes up to 30 years to consolidate to a trafficable surface compared to weeks for TRO. TRO allows MFT to be consumed more quickly than it is produced, reducing need to build more tailings ponds, operates independent of plant operations, accelerates the reclamation time frame, and offers enhanced flexibility in final tailings placement sites. TRO also creates a dry landscape, to which well established reclamation techniques can be applied. Dried MFT is a new material type, and research is exploring optimum reclamation techniques. 2 figs.

  11. Trace metals in heavy crude oils and tar sand bitumens

    Energy Technology Data Exchange (ETDEWEB)

    Reynolds, J.G.

    1990-11-28

    Fe, Ni, and V are considered trace impurities in heavy crude oils and tar sand bitumens. In order to understand the importance of these metals, we have examined several properties: (1) bulk metals levels, (2) distribution in separated fractions, (3) size behavior in feeds and during processing, (4) speciation as a function of size, and (5) correlations with rheological properties. Some of the results of these studies show: (1) V and Ni have roughly bimodal size distributions, (2) groupings were seen based on location, size distribution, and Ni/V ratio of the sample, (3) Fe profiles are distinctively different, having a unimodal distribution with a maximum at relatively large molecular size, (4) Fe concentrations in the tar sand bitumens suggest possible fines solubilization in some cases, (5) SARA separated fractions show possible correlations of metals with asphaltene properties suggesting secondary and tertiary structure interactions, and (6) ICP-MS examination for soluble ultra-trace metal impurities show the possibility of unexpected elements such as U, Th, Mo, and others at concentrations in the ppB to ppM range. 39 refs., 13 figs., 5 tabs.

  12. Ottawa Sand for Mechanics of Granular Materials (MGM) Experiment

    Science.gov (United States)

    2000-01-01

    What appear to be boulders fresh from a tumble down a mountain are really grains of Ottawa sand, a standard material used in civil engineering tests and also used in the Mechanics of Granular Materials (MGM) experiment. The craggy surface shows how sand grans have faces that can cause friction as they roll and slide against each other, or even causing sticking and form small voids between grains. This complex behavior can cause soil to behave like a liquid under certain conditions such as earthquakes or when powders are handled in industrial processes. MGM uses the microgravity of space to simulate this behavior under conditions that carnot be achieved in laboratory tests on Earth. MGM is shedding light on the behavior of fine-grain materials under low effective stresses. Applications include earthquake engineering, granular flow technologies (such as powder feed systems for pharmaceuticals and fertilizers), and terrestrial and planetary geology. Nine MGM specimens have flown on two Space Shuttle flights. Another three are scheduled to fly on STS-107. The principal investigator is Stein Sture of the University of Colorado at Boulder. These images are from an Electron Spectroscopy for Chemical Analysis (ESCA) study conducted by Dr. Binayak Panda of IITRI for Marshall Space Flight Center (MSFC). (Credit: NASA/MSFC)

  13. Hydraulic characteristics of oil sands hydrotransport systems

    Energy Technology Data Exchange (ETDEWEB)

    Coward, J. M. (Syncrude Canada Ltd., Research Centre, Edmonton, AB (Canada)); McDonnell, B. (Syncrude Canada Ltd., Edmonton, AB (Canada))

    1999-01-01

    Operating characteristics of a large-scale hydrotransport system which was installed at Syncrude in 1997 to transport oil sands to the processing plant about 4.5 km away is described. While in transit, the bitumen also undergoes conditioning. Some unique characteristics associated with the presence of bitumen have been observed . For example, headlosses in the horizontal pipeline were close to the water line for normal oil sands, but considerably higher for high grade oil sands. Pump head ratios and efficiency ratios were observed to be affected negatively by the presence of high grade oil sands. Slurry density had the same negative effect. The overall result of lower pump efficiencies and larger headloss with higher grade ore is a general degradation of system performance. The lesson to be learned from this observation is that when handling slurries with higher oil sand grades, it is essential to increase pumping capacity . 9 refs., 8 figs.

  14. Hydraulic characteristics of oil sands hydrotransport systems

    Energy Technology Data Exchange (ETDEWEB)

    Coward, J. M. [Syncrude Canada Ltd., Research Centre, Edmonton, AB (Canada); McDonnell, B. [Syncrude Canada Ltd., Edmonton, AB (Canada)

    1999-10-01

    Operating characteristics of a large-scale hydrotransport system which was installed at Syncrude in 1997 to transport oil sands to the processing plant about 4.5 km away is described. While in transit, the bitumen also undergoes conditioning. Some unique characteristics associated with the presence of bitumen have been observed . For example, headlosses in the horizontal pipeline were close to the water line for normal oil sands, but considerably higher for high grade oil sands. Pump head ratios and efficiency ratios were observed to be affected negatively by the presence of high grade oil sands. Slurry density had the same negative effect. The overall result of lower pump efficiencies and larger headloss with higher grade ore is a general degradation of system performance. The lesson to be learned from this observation is that when handling slurries with higher oil sand grades, it is essential to increase pumping capacity . 9 refs., 8 figs.

  15. Earth-like sand fluxes on Mars.

    Science.gov (United States)

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

    2012-05-09

    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.

  16. Ecological release in White Sands lizards.

    Science.gov (United States)

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

    2011-12-01

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

  17. Choosing an optimum sand control method

    Directory of Open Access Journals (Sweden)

    Ehsan Khamehchi

    2015-06-01

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

  18. Developing new markets for oil sands products

    International Nuclear Information System (INIS)

    Crandall, G.

    2004-01-01

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

  19. Context matters: community characteristics and mental health among war-affected youth in Sierra Leone.

    Science.gov (United States)

    Betancourt, Theresa S; McBain, Ryan; Newnham, Elizabeth A; Brennan, Robert T

    2014-03-01

    Worldwide, over one billion children and adolescents live in war-affected settings. At present, only limited research has investigated linkages between disrupted social ecology and adverse mental health outcomes among war-affected youth. In this study, we examine three community-level characteristics - social disorder and collective efficacy within the community, as reported by caregivers, and perceived stigma as reported by youth - in relation to externalizing behaviors and internalizing symptoms among male and female former child soldiers in postconflict Sierra Leone. A total of 243 former child soldiers (30% female, mean age at baseline: 16.6 years) and their primary caregivers participated in interviews in 2004 and 2008, as part of a larger prospective cohort study of war-affected youth in Sierra Leone. Two-point growth models were estimated to examine the relationship between community-level characteristics and externalizing and internalizing outcomes across the time points. Both social disorder within the community, reported by caregivers, and perceived stigma, reported by youth, positively covaried with youths' externalizing and internalizing scores - indicating that higher levels of each at baseline and follow-up were associated with higher levels of mental health problems at both time points (p mental health outcomes was nonsignificant (p > .05). This study offers a rare glimpse into the role that the postconflict social context plays in shaping the mental health among former child soldiers. Results indicate that both social disorder and perceived stigma within the community demonstrate an important relationship to externalizing and internalizing problems among adolescent ex-combatants. Moreover, these relationships persisted over a 4-year period of follow-up. These results underscore the importance of the postconflict social environment and the need to develop postconflict interventions that address community-level processes in addition to the needs

  20. Pattern of skin infections in black Africans of Sierra Leone (West Africa

    Directory of Open Access Journals (Sweden)

    Bari Arfan ul

    2007-01-01

    Full Text Available Background: Physical differences among human populations may lead to variable prevalence of skin disorders in different ethnicities. Skin infections are one of the important curable and largely preventable categories of skin disorders in the communities. Aim: The purpose of the study was to see the patterns of skin infections in black Africans of Sierra Leone and to compare with other ethnic populations. Materials and Methods: Local blacks of all age groups presenting in Dermatology out patient department of Pak Field Hospital (established as a part of UN peacekeeping mission in Sierra Leone were included (from Nov 2004 to Oct 2005. Relevant clinical history and physical examination was done. Laboratory investigations were carried out when indicated. Skin diseases were broadly classified into two major categories i.e., infective and noninfective. Among infective, sexually transmitted infections were again separated. Nonblack settlers in the area and UN troops were not included in the study. Data was recorded and analyzed by Microsoft Excel program. Results: 3011 patients belonging to different local tribes having a variety of skin disorders were seen. Patients were of all ages and both sexes ranging from one month to 73 years of age. The Infective skin disorders were seen in 61.7% patients and most prevalent were superficial fungal infections (41.2% followed by, sexually transmitted infections (9.9% and parasitic infections (6.5%. Bacterial and viral infections were rare and so was the scabies. More than 90% parasitic infections were onchocerciasis with full spectrum of cutaneous manifestations. Conclusion: Pattern of skin infections in blacks varies considerably from other ethnic races. Environmental factors, geographical location and free existence of vector for onchocerciasis in West African region, possibly have a significant influence in this variable prevalence.

  1. Ebola Virus Disease Complications as Experienced by Survivors in Sierra Leone

    Science.gov (United States)

    Tiffany, Amanda; Vetter, Pauline; Mattia, John; Dayer, Julie-Anne; Bartsch, Maria; Kasztura, Miriam; Sterk, Esther; Tijerino, Ana Maria; Kaiser, Laurent; Ciglenecki, Iza

    2016-01-01

    Background. Thousands of people have survived Ebola virus disease (EVD) during the ongoing outbreak. However, data about the frequency and risk factors of long-term post-EVD complications remain scarce. We describe the clinical characteristics of EVD survivors followed in a survivor clinic in Freetown, Sierra Leone. Methods. A survivor clinic opened within an Ebola treatment center compound in Freetown, Sierra Leone. At each visit, clinical and psychological assessments were conducted and free treatment was offered. Survivors were referred to a partner's hospitals if their condition could not be managed in the clinic. We used routinely collected data from the clinic to describe long-term complications of EVD and their risk factors. Results. A total of 1001 medical consultations for 166 patients were performed between 3 February and 21 June 2015. The most frequent complaints and diagnoses were arthralgia (n = 129 [77.7%]), fatigue (n = 116 [69.8%]), abdominal pain (n = 90 [54.2%]), headache (n = 87 [52.4%]), anemia (n = 83 [50%]), skin disorders (n = 81 [48.8%]), back pain (n = 54 [32.5%]), and alopecia (n = 53 [31.9%]). Ocular complications were diagnosed in 94 survivors (56.7%); uveitis was the most common (n = 57 [34%]). Survivors were 10 times more likely to develop uveitis post-EVD if they presented with red/injected eyes during the acute phase of their illness. Conclusions. Post-EVD complications among our patients were similar to those described previously and were detected early following the acute phase of disease. Follow-up of survivors should begin immediately after discharge to address sequelae as they arise and reduce the potential for development of long-term disabilities such as blindness. PMID:27001797

  2. The status of maternal and newborn care services in Sierra Leone 8 years after ceasefire.

    Science.gov (United States)

    Oyerinde, Koyejo; Harding, Yvonne; Amara, Philip; Kanu, Rugiatu; Shoo, Rumishael; Daoh, Kizito

    2011-08-01

    To conduct a needs assessment for emergency obstetric care (EmOC) to address the unacceptably high maternal and newborn mortality indices in Sierra Leone 8 years after the end of the civil war. From June to August 2008, a cross-sectional survey was conducted of health facilities in Sierra Leone offering delivery services. Assessment tools were local adaptations of tools developed by the Averting Maternal Death and Disability program at Columbia University, New York, USA. There were enough comprehensive EmOC (CEmOC) facilities in the country but they were poorly distributed. There were no basic EmOC (BEmOC) facilities. Few facilities (37% of hospitals and 2% of health centers) were able to perform assisted vaginal delivery (AVD), and 3 potentially BEmOC facilities did not meet the standard only because they did not perform AVD. Severe shortages in staff, equipment, and supplies, and unsatisfactory supply of utilities severely hampered the delivery of quality EmOC services. Demand for maternity and newborn services was low, which may have been related to the poor quality and the high/unpredictable out-of-pocket cost of such services. Significant increases in the uptake of institutional delivery services, the linkage of remote health workers to the health system, and the recruitment of midwives, in addition to rapid expansion in the training of health workers (including training in midwifery and obstetric surgery skills), are urgently needed to improve the survival of mothers and newborns. Copyright © 2011 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved.

  3. Herbal medicine use among hypertensive patients attending public and private health facilities in Freetown Sierra Leone.

    Science.gov (United States)

    James, Peter Bai; Kamara, Halimatu; Bah, Abdulai Jawo; Steel, Amie; Wardle, Jon

    2018-05-01

    This study aimed to determine the prevalence, determinants and pattern of herbal medicine use among hypertensive patients in Freetown. We conducted a cross-sectional study among hypertensive patients attending public and private health facilities in Freetown, Sierra Leone between August and October 2016. We analyzed the data using SPSS version 24. We used Chi-square, Fisher exact two-tailed test and regression analysis for data analysis. A p-value less than 0.05 was considered statistically significant. Out of 260 study participants, over half (n = 148, 56.9%) reported using herbal medicine for the treatment of hypertension alone or together with comorbid condition(s). The most commonly used herbal medicine among users were honey (n = 89, 33.3%), moringa (n = 80, 30.0%) and garlic (n = 73, 27.3%). No significant difference existed between users and non-users of herbal medicine with regards to socio-demographic and health-related factors. The majority (n = 241, 92.7%) of respondents considered herbal medicine beneficial if it was recommended by a healthcare provider yet 85.1% (n = 126) did not disclose their herbal medicine use to their health care provider. There is a high use of herbal medicines among hypertensive patients in Freetown, Sierra Leone. It is essential for healthcare providers to take heed of the findings of this study and routinely ask their patients about their herbal medicine use status. Such practice will provide the opportunity to discuss the benefits and risks of herbal medicine use with the aim of maximizing patient desired therapeutic outcomes. Copyright © 2018 Elsevier Ltd. All rights reserved.

  4. Development of a set of community-informed Ebola messages for Sierra Leone

    Science.gov (United States)

    de Bruijne, Kars; Jalloh, Alpha M.; Harris, Muriel; Abdullah, Hussainatu; Boye-Thompson, Titus; Sankoh, Osman; Jalloh, Abdul K.; Jalloh-Vos, Heidi

    2017-01-01

    The West African Ebola epidemic of 2013–2016 was by far the largest outbreak of the disease on record. Sierra Leone suffered nearly half of the 28,646 reported cases. This paper presents a set of culturally contextualized Ebola messages that are based on the findings of qualitative interviews and focus group discussions conducted in 'hotspot' areas of rural Bombali District and urban Freetown in Sierra Leone, between January and March 2015. An iterative approach was taken in the message development process, whereby (i) data from formative research was subjected to thematic analysis to identify areas of community concern about Ebola and the national response; (ii) draft messages to address these concerns were produced; (iii) the messages were field tested; (iv) the messages were refined; and (v) a final set of messages on 14 topics was disseminated to relevant national and international stakeholders. Each message included details of its rationale, audience, dissemination channels, messengers, and associated operational issues that need to be taken into account. While developing the 14 messages, a set of recommendations emerged that could be adopted in future public health emergencies. These included the importance of embedding systematic, iterative qualitative research fully into the message development process; communication of the subsequent messages through a two-way dialogue with communities, using trusted messengers, and not only through a one-way, top-down communication process; provision of good, parallel operational services; and engagement with senior policy makers and managers as well as people in key operational positions to ensure national ownership of the messages, and to maximize the chance of their being utilised. The methodological approach that we used to develop our messages along with our suggested recommendations constitute a set of tools that could be incorporated into international and national public health emergency preparedness and

  5. Glikman : maadeafääri süüdistust ei pruugi tulla / Leon Glikman ; interv. Kärt Anvelt

    Index Scriptorium Estoniae

    Glikman, Leon, 1957-

    2008-01-01

    Intervjuu vandeadvokaat Leon Glikmaniga, kelle büroo kaitseb maadevahetusega seotud kriminaalasjas kahtlustatavaid Toomas Annust ja Andres Sarrit. Intervjuu sissejuhatus puudutab tööandjate keskliidu oktoobris 2007 koostatud pöördumist peaministri poole

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

    Science.gov (United States)

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

    2016-12-01

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

  7. Determining gas hydrate distribution in sands using integrated analysis of well log and seismic data in the Terrebonne Basin, Gulf of Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Hillman, Jess; Cook, Ann; Daigle, Hugh; Nole, Michael; Malinverno, Alberto

    2016-09-30

    The Terrebonne Basin is a salt bounded mini-basin in the northeast section of the Walker Ridge protraction area in the Gulf of Mexico, and the main site for an upcoming gas-hydrate focused International Ocean Discovery Program (IODP) cruise. The basin is infilled by an increasingly mud rich sedimentary sequence with several 5-15 meter gas-hydrate filled sand units of Miocene to Pliocene age overlying the up-domed salt. These gas-hydrate filled sand units can be identified in logging while drilling data from two existing wells in the Terrebonne Basin, drilled in 2009 by the Gas Hydrate Joint Industry Project (JIP) Leg 2. The sand units are cross cut by a distinct bottom-simulating reflector (BSR), and are clearly characterized by a polarity reversal in the sand units. The polarity reversal is caused by a positive gas-hydrate filled sand within the stability zone changing to negative gas-bearing sand. Using well data and calculated synthetic seismogram well ties we are able to identify several additional 1-4 meter gas-hydrate and water-saturated sand units associated with thick (100-200 m-thick), fine grained, hydrate bearing fractured units in the upper sedimentary sequence on the seismic data. Following on previous work, we propose that microbial generation of methane occurring within the fine-grained, fractured units acts as a source for gas hydrate formation in the thin sands. In contrast, it has been proposed that the gas hydrate in the 5-15 m-thick sands first discovered by the JIP was originates from a deeper thermogenic source. Through correlating hydrate occurrence in sands from well data, to amplitudes derived from the seismic data, we can estimate possible distribution of hydrate across the basin. Overall, we find the Terrebonne basin to be a complex gas hydrate system with multiple mechanisms of methane generation and migration.

  8. Patients' Satisfaction with Lower-limb Prosthetic and Orthotic Devices and Service delivery in Sierra Leone and Malawi.

    Science.gov (United States)

    Magnusson, Lina; Ahlström, Gerd

    2017-02-01

    People with disabilities have the right to personal mobility and available and affordable assistive technology, according to the Convention of Rights of Persons with Disabilities. The aims were to investigate similarities and differences between Sierra Leone and Malawi concerning participants' mobility and satisfaction with their lower-limb prosthetic or orthotic device and related service delivery, and to identify variables associated with patients' satisfaction with assistive devices and associated services in the entire study group from these two low-income countries. Questionnaires, including QUEST, were answered by 222 patients in Sierra Leone and Malawi. Eighty-six per cent of assistive devices were in use, but half needed repair. One third of participants reported pain when using their assistive device. A higher percentage (66%) of participants in Sierra Leone had difficulties or could not walk at all on uneven ground compared with 42% in Malawi. The majority in both countries had difficulties or could not walk at all up and down hills, or on stairs. Participants in both countries were quite satisfied (mean 3.7-3.9 of 5) with their assistive device. Participants were most dissatisfied with: comfort (46%), dimensions (39%), and safety (38%) of their assistive device. In Sierra Leone participants were less satisfied than in Malawi with service delivery (mean 3.7; 4.4, p < .001). Access to repairs and servicing of their assistive device was considered the most important item. In Sierra Leone patients were less satisfied with follow-up services (41%) than patients in Malawi were (22%). The strongest association with satisfaction with assistive device was pain, and for satisfaction with service, country. The general condition of devices and the ability to walk on uneven ground were associated with both satisfaction with assistive devices and service received. Participants reported high levels of use and mobility with their assistive device, in spite of pain

  9. Understanding the Causes of Civil Wars in Post-Colonial Sub-Saharan Africa. Case study: Sierra Leone and the Role of women in the Search for Peace

    OpenAIRE

    Sesay, Adama

    2013-01-01

    It is widely understood or assumed among scholars like Thomas Weiss, that civil wars in Africa are mainly wars for natural resources. This statement needs careful evaluation, and it is for this reason that this study will use Weiss`s theories on the causes of wars in sub-Sahara Africa as a background for understanding the Sierra Leone conflict. In addition, as the title implies, this paper further aims to investigate the war in Sierra Leone and most...

  10. Granular encapsulation of light hydrophobic liquids (LHL) in LHL-salt water systems: Particle induced densification with quartz sand.

    Science.gov (United States)

    Boglaienko, Daria; Tansel, Berrin; Sukop, Michael C

    2016-02-01

    Addition of granular materials to floating crude oil slicks can be effective in capturing and densifying the floating hydrophobic phase, which settles by gravity. Interaction of light hydrophobic liquids (LHL) with quartz sand was investigated in LHL-salt water systems. The LHLs studied were decane, tetradecane, hexadecane, benzene, toluene, ethylbenzene, m-xylene, and 2-cholorotoluene. Experiments were conducted with fine quartz sand (passing sieve No. 40 with openings 0.425 mm). Each LHL was dyed with few crystals of Sudan IV dye for ease of visual observation. A volume of 0.5 mL of each LHL was added to 100 mL salt water (34 g/L). Addition of one gram of quartz sand to the floating hydrophobic liquid layer resulted in formation of sand-encapsulated globules, which settled due to increased density. All LHLs (except for a few globules of decane) formed globules covered with fine sand particles that were heavy enough to settle by gravity. The encapsulated globules were stable and retained their shape upon settling. Polarity of hydrophobic liquids as the main factor of aggregation with minerals was found to be insufficient to explain LHL aggregation with sand. Contact angle measurements were made by submerging a large quartz crystal with the LHL drop on its surface into salt water. A positive correlation was observed between the wetting angle of LHL and the LHL volume captured (r = 0.75). The dependence of the globule density on globule radius was analyzed in relation to the coverage (%) of globule surface (LHL-salt water interface) by fine quartz particles. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. A Laboratory Experiment on the Evolution of a Sand Gravel Reach Under a Lack of Sediment Supply

    Science.gov (United States)

    Orru, C.; Chavarrias, V.; Ferrara, V.; Blom, A.

    2014-12-01

    A flume experiment was conducted to examine the evolution of a sand-gravel reach under a lack of sediment supply. The experimental data are used to validate a numerical sand-gravel model. A bed composed of a bi-modal sediment mixture is installed with a uniform slope and an imposed gradual fining pattern. Initially, the sand fraction gradually increases in streamwise direction until the bed is fully composed of sand. The water discharge and downstream water level were constant, and the sediment feed rate was equal to zero. The experiment was dominated by bed load, partial transport, and a subcritical flow regime was imposed. The flow rate was such that only sand was mobile (partial transport), which led to a coarsening over the upstream reach and a gradual reduction of the sediment transport rate during the experiment. New equipment was used to measure the evolution of the grain size distribution of the bed surface during the experiment over the entire flume using image analysis. In the upstream reach we observed a gradual coarsening over time and the formation of an armour layer, which resulted in a more abrupt transition in grain size of the bed surface. Bed degradation increased in streamwise direction. This is due to the initial streamwise increase in the availability of sand in the bed. The different volume fraction content of sand in the bed allowed for the gravel to sink more in the downstream part of the upstream reach. The sand reach suffered from a larger degradation. Finally, we see one reach dominated by sand, small bedforms, and a small bed slope, and a gravel reach dominated by a larger bed slope.

  12. Sand Flies and Their Control Methods.

    Science.gov (United States)

    Çetin, Hüseyin; Özbel, Yusuf

    2017-06-01

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

  13. Early diagenesis of eolian dune and interdune sands at White Sands, New Mexico

    Science.gov (United States)

    Schenk, C.J.; Fryberger, S.G.

    1988-01-01

    The degree of early diagenesis in eolian dune and interdune sands at White Sands, New Mexico, is largely a function of the relationship between sand location and the water table. Most active and vegetation-stabilized dune sands are in the vadose zone, whereas interdune sands are in the capillary fringe and phreatic zones. Crystallographically controlled dissolution of the framework gypsum grains results in elongate, prismatic etch pits on sand grains from the capillary fringe and phreatic zones, whereas dissolution of sand grains in the vadose zone is slight, causing minute irregularities on grain surfaces. Vadose water percolating through the sand is manifest as meniscus layers. Consequently, dune sands in the vadose zone are cemented mainly by meniscus-shaped gypsum at grain contacts. Pendant cements formed on the lower margins of some sand grains. Cementation in the capillary fringe and the phreatic zone is more extensive than the vadose regardless of strata type. Typically, well-developed gypsum overgrowths form along the entire edge of a grain, or may encompass the entire grain. Complex diagenetic histories are suggested by multiple overgrowths and several episodes of dissolution on single grains, attesting to changing saturation levels with respect to gypsum in the shallow ground water. These changes in saturation are possibly due to periods of dilution by meteoric recharge, alternating with periods of concentration of ions and the formation of cement due to evaporation through the capillary fringe. ?? 1988.

  14. Sudan challenges the sand dragon.

    Science.gov (United States)

    Tinker, J

    1978-01-01

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

  15. Morphodynamical Evolution of Sand Ripples

    Science.gov (United States)

    Rousseaux, G.; Stegner, A.; Wesfreid, J. E.

    A flat particle bed under an oscillatory viscous flow is generally unstable and leads to the formation of ripples. Such patterns are encountered in coastal regions where sea waves in shallow waters induce a back and forth fluid motion on sandy sea beds. Using a cylindrical oscillating tank, we have studied in laboratory, at very high resolution, the wavelength selection, the morphology and the temporal evolution of theses ripples . Three dynamical stages can be observed. Initially, the rolling of individual grains on the flat sand bed induces small rolling grain ripples. At this stage the wavelength selection depends only on the grain diameter, the viscous boundary layer and the viscous length. In a second stage, the ripples follow a coarsening process which increase both the height and the wavelength of the patterns. For few cases, especially close to the onset of ripple formation, a logarithmic growth of the wavelength is observed. Then, if we wait long enough the system always evolves to a final vortex ripple state which is mainly controlled by the amplitude of the fluid excursion.

  16. Risk in the "Red Zone": Outcomes for Children Admitted to Ebola Holding Units in Sierra Leone Without Ebola Virus Disease.

    Science.gov (United States)

    Fitzgerald, F; Wing, K; Naveed, A; Gbessay, M; Ross, J C G; Checchi, F; Youkee, D; Jalloh, M B; Baion, D; Mustapha, A; Jah, H; Lako, S; Oza, S; Boufkhed, S; Feury, R; Bielicki, J; Williamson, E; Gibb, D M; Klein, N; Sahr, F; Yeung, S

    2017-07-01

    We collected data on 1054 children admitted to Ebola Holding Units in Sierra Leone and describe outcomes of 697/1054 children testing negative for Ebola virus disease (EVD) and accompanying caregivers. Case-fatality was 9%; 3/630 (0.5%) children discharged testing negative were readmitted EVD-positive. Nosocomial EVD transmission risk may be lower than feared. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America.

  17. Localized Structures on Periodic Background Wave of (2+1)-Dimensional Boiti-Leon-Pempinelli System via an Object Reduction

    Science.gov (United States)

    Fang, Jian-Ping; Ma, Song-Hua; Fei, Jin-Xi; Hong, Bi-Hai; Zheng, Chun-Long

    2007-11-01

    In this paper, we present an object reduction for nonlinear partial differential equations. As a concrete example of its applications in physical problems, this method is applied to the (2+1)-dimensional Boiti-Leon-Pempinelli system, which has the extensive physics background, and an abundance of exact solutions is derived from some reduction equations. Based on the derived solutions, the localized structures under the periodic wave background are obtained.

  18. Case report and brief commentary: Wuchereria bancrofti and Onchocerca volvulus co-infection in a refugee from Sierra Leone.

    Science.gov (United States)

    Rajkumar, Michael J; Wright, Stephanie; Aslanzadeh, Jaber

    2005-01-01

    Filarial infection is endemic in the tropics and is a public health problem in Africa, Asia, South and Central America, and the Pacific Islands. Co-infection with filarial nematodes, if unrecognized, can result in untoward therapeutic consequences. We report a case of co-infection of Wuchereria bancrofti and Onchocerca volvulus that was diagnosed by direct blood smear (W. bancrofti ) and serology (O. volvulus) in a native of Sierra Leone. We comment briefly on the therapeutic implications of the co-infection.

  19. Detection and Partial Characterization of Simian Immunodeficiency Virus SIVsm Strains from Bush Meat Samples from Rural Sierra Leone

    OpenAIRE

    Apetrei, Cristian; Metzger, Michael J.; Richardson, David; Ling, Binhua; Telfer, Paul T.; Reed, Patricia; Robertson, David L.; Marx, Preston A.

    2005-01-01

    Human immunodeficiency virus type 2 (HIV-2) originated from simian immunodeficiency viruses (SIVs) that naturally infect sooty mangabeys (SMs; Cercocebus atys). In order to further investigate the relationship between HIV-2 and SIVsm, the SIV specific to the SM, we characterized seven new SIVsm strains from SMs sold in Sierra Leone markets as bush meat. The gag, pol, and env sequences showed that, while the viruses of all seven SMs belonged to the SIVsm-HIV-2 lineage, they were highly diverge...

  20. Store Type and Demographic Influence on the Availability and Price of Healthful Foods, Leon County, Florida, 2008

    OpenAIRE

    Leone, Angela F.; Lee, Jung Sun; Rigby, Samantha; Kurtz, Hilda; Johnson, Mary Ann; Betterley, Connie; Park, Sohyun

    2011-01-01

    Introduction The availability of healthful foods varies by neighborhood. We examined the availability and price of more healthful foods by store type, neighborhood income level, and racial composition in a community with high rates of diet-related illness and death. Methods We used the modified Nutrition Environment Measures Survey in Stores to conduct this cross-sectional study in 2008. We surveyed 73 stores (29% supermarkets, 11% grocery stores, and 60% convenience stores) in Leon County, F...

  1. Changes in catastrophic health expenditure in post-conflict Sierra Leone: an Oaxaca-blinder decomposition analysis.

    Science.gov (United States)

    Edoka, Ijeoma; McPake, Barbara; Ensor, Tim; Amara, Rogers; Edem-Hotah, Joseph

    2017-09-04

    At the end of the eleven-year conflict in Sierra Leone, a wide range of policies were implemented to address both demand- and supply-side constraints within the healthcare system, which had collapsed during the conflict. This study examines the extent to which households' exposure to financial risks associated with seeking healthcare evolved in post-conflict Sierra Leone. This study uses the 2003 and 2011 cross-sections of the Sierra Leone Integrated Household Survey to examine changes in catastrophic health expenditure between 2003 and 2011. An Oaxaca-Blinder decomposition approach is used to quantify the extent to which changes in catastrophic health expenditure are attributable to changes in the distribution of determinants (distributional effect) and to changes in the impact of these determinants on the probability of incurring catastrophic health expenditure (coefficient effect). The incidence of catastrophic health expenditure decreased significantly by 18% from approximately 50% in 2003 t0 32% in 2011. The decomposition analysis shows that this decrease represents net effects attributable to the distributional and coefficient effects of three determinants of catastrophic health expenditure - ill-health, the region in which households reside and the type of health facility used. A decrease in the incidence of ill-health and changes in the regional location of households contributed to a decrease in catastrophic health expenditure. The distributional effect of health facility types observed as an increase in the use of public health facilities, and a decrease in the use of services in facilities owned by non-governmental organizations (NGOs) also contributed to a decrease in the incidence of catastrophic health expenditure. However, the coefficient effect of public health facilities and NGO-owned facilities suggests that substantial exposure to financial risk remained for households utilizing both types of health facilities in 2011. The findings support the

  2. Fine structure and distribution pattern of antennal sensilla of Lutzomyia longipalpis (Diptera: Psychodidae) sand flies.

    Science.gov (United States)

    Fernandes, Fernando de Freitas; Bahia-Nascimento, Ana Cristina; Pinto, Luciana Conceição; Leal, Cynthia de Sousa; Secundino, Nágila Francinete Costa; Pimenta, Paulo Filemon Paolucci

    2008-11-01

    The specific aims of this work were to examine the antennal sensilla of Lutzomyia longipalpis (Lutz & Neiva 1912) (Diptera: Psychodidae) adults and to characterize their typology and topography, with special attention to olfactory sensilla. The surfaces of the antennal segments of Lu. longipalpis males and females were studied by scanning electron microscopy (SEM). Lu. longipalpis used in the current study were obtained from a colony originating from Lapinha Cave, Minas Gerais state, Brazil. Microtrichiae and 11 subtypes of sensilla were observed and characterized according to the following categories: five subtypes of trichoid sensilla (short, medium, long blunt-tipped, long pointed-tipped, and apical), two coeloconic sensilla (grooved and praying hands), and campaniform, chaetic, basiconic, and squamiform sensilla. SEM analyses showed few differences between males and females in the typology, topography, and quantity of antennal sensilla described. The current study is the first to identify several categories of antennal sensilla of the genus Lutzomyia and their distribution patterns. The identification of these sensillar types may be important in planning future electrophysiological studies to develop alternative measures of control and monitoring of Lu. longipalpis.

  3. The exceptional sediment load of fine-grained dispersal systems: Example of the Yellow River, China.

    Science.gov (United States)

    Ma, Hongbo; Nittrouer, Jeffrey A; Naito, Kensuke; Fu, Xudong; Zhang, Yuanfeng; Moodie, Andrew J; Wang, Yuanjian; Wu, Baosheng; Parker, Gary

    2017-05-01

    Sedimentary dispersal systems with fine-grained beds are common, yet the physics of sediment movement within them remains poorly constrained. We analyze sediment transport data for the best-documented, fine-grained river worldwide, the Huanghe (Yellow River) of China, where sediment flux is underpredicted by an order of magnitude according to well-accepted sediment transport relations. Our theoretical framework, bolstered by field observations, demonstrates that the Huanghe tends toward upper-stage plane bed, yielding minimal form drag, thus markedly enhancing sediment transport efficiency. We present a sediment transport formulation applicable to all river systems with silt to coarse-sand beds. This formulation demonstrates a remarkably sensitive dependence on grain size within a certain narrow range and therefore has special relevance to silt-sand fluvial systems, particularly those affected by dams.

  4. Using of Glass Wastes as a Fine Aggregate in Concrete Mixture

    Directory of Open Access Journals (Sweden)

    Mohammad F. Al-Deen

    2013-04-01

    Full Text Available In this study, the waste glass (WG is considered as a fine aggregate in the concretemixture. WG is used after grinding to size according to Iraqi sand specificationsNo.45. The waste glass has been used instead of sand in different proportions whichare 0%, 33%, 66% and 100%. The effects of WG on compressive strength of theconcrete and unit weight are analysed. As results of this study, WG is determined tohave a significant effect upon the reduction of its compressive strength and there is asignificant decreasing of its unit weight. As for cost analysis, it was determined tolower the cost of concrete production. This study was an environmental one inconsideration of the fact that WG could be used in the concrete as fine aggreagateswithout the need for a high cost or rigorous energy.

  5. Evaluation of the performance of the cross-flow air classifier in manufactured sand processing via CFD-DEM simulations

    Science.gov (United States)

    Petit, H. A.; Irassar, E. F.; Barbosa, M. R.

    2018-01-01

    Manufactured sands are particulate materials obtained as by product of rock crushing. Particle sizes in the sand can be as high as 6 mm and as low as a few microns. The concrete industry has been increasingly using these sands as fine aggregates to replace natural sands. The main shortcoming is the excess of particles smaller than Dust). This problem has been traditionally solved by a washing process. Air classification is being studied to replace the washing process and avoid the use of water. The complex classification process can only been understood with the aid of CFD-DEM simulations. This paper evaluates the applicability of a cross-flow air classifier to reduce the amount of dust in manufactured sands. Computational fluid dynamics (CFD) and discrete element modelling (DEM) were used for the assessment. Results show that the correct classification set up improves the size distribution of the raw materials. The cross-flow air classification is found to be influenced by the particle size distribution and the turbulence inside the chamber. The classifier can be re-designed to work at low inlet velocities to produce manufactured sand for the concrete industry.

  6. [Social and economic impact of chicken pox vaccine at 15 months of age. Castile and Leon, Spain, 2004].

    Science.gov (United States)

    Pérez-Rubio, A; Castrodeza Sanz, J J; Gil Costa, M; Luquero Alcalde, F J; Eiros Bouza, J; Ortiz de Lejarazu, R

    2008-01-01

    Chicken pox is a mainly childhood contagious disease caused by the Varicella Zoster Virus which gives rise to major healthcare and social costs. In 2005, Castile and Leon added chicken pox vaccine injections to its childhood vaccination schedule for eleven year-olds subject to coming down with this disease. This strategy does not modify the major mobility generated thereby at younger ages. This study is aimed at evaluating the profitability of systematic vaccination for chicken pox in infants 15 months of age in Castile and Leon. An economic cost-benefit evaluation has been set out by jeans of a decision-making tree. A fictitious cohort of 100,000 children in Castile and Leon having reached 15 months of age in 2004 is studied, to whom the chicken pox vaccine would be administered in conjunction with the mumps, measles, rubella vaccines. This study is approached from the social standpoint. The time horizon selected was that of up until the study cohort was to reach 15 years of age, applying a 3% discount rate. A sensitivity analysis was made for evaluating the uncertainty of some variables... The cost-benefit ratio of adding this vaccine to the childhood vaccination schedule amounts to 1.23. From the social standpoint, administering chicken pox vaccine in conjunction with the mumps, measles, rubella vaccines show itself to be profitable. The profitability is modified both if a second dose of vaccine is added as well as if only the direct healthcare costs are analyzed.

  7. Displacement pile installation effects in sand

    NARCIS (Netherlands)

    Beijer-Lundberg, A.

    2015-01-01

    Installation effects govern the post-installation behaviour of displacement piles in sand. These effects are currently not completely understood. Suitable experimental techniques to model these installation effects include field, laboratory and experimental models. In the current thesis a

  8. Complicated feature of atmospheric aerosols shown in the yellow sand events in Japan

    Science.gov (United States)

    Mukai, Sonoyo; Sano, Itaru; Mukai, Makiko

    It is well known that aerosol has a significant potential to the earth's climate. The aerosol distributions in Asia are very complex due to the increasing emissions of small anthropogenic particles associated with economic growth and large dust particles called yellow sands transported on the westerly wind from the continental desert areas. In this study, aerosol properties in the yellow sand events are focused and analyzed from comprehensive aspects. Yellow sand events have often happened in spring. Therefore they have been called 'spring haze' involving an expectation of coming spring to Japan. However the recent yellow sand events are too heavy and too severe to call 'spring haze' due to the increasing of desert areas and contamination with the anthropogenic emissions. The sun/sky photometry has been undertaken at NASA/AERONET stations in Osaka, Shirahama and Noto in Japan. Suspended particulate matter (PM) and OBC (Optical Black Carbon) have been simultaneously measured there. The simultaneous monitoring of aerosols and PM provides such a relation between them as there is a linear correlation between PM concentrations and AOT, which indicates that AOT can be estimated from PM data, and vice versa. It is found that the value of aerosol optical thickness (AOT) during aerosol event is more than double its usual value, and fine anthropogenic particles dominate even during dust events in Japan. It is of interest to mention that yellow sand events in Japan seem to be caused by a mixture of non-absorbing coarse dust and other small haze particles, especially shown in the event in May 2007. A new instrument of NIES/LIDAR network to be set at AERONET/Osaka station in March 2008 is expected to provide us with the vertical distribution of yellow sand particles. Furthermore the model simulations with SPRINTARS/AGCM/CCSR/NIES/FRCGC and satellite data will be available for our better understanding of the beyond pollution of the atmosphere.

  9. Engineering properties of concrete with partial utilization of used foundry sand.

    Science.gov (United States)

    Manoharan, Thiruvenkitam; Laksmanan, Dhamothiran; Mylsamy, Kaliyannan; Sivakumar, Pandian; Sircar, Anirbid

    2018-01-01

    Solid wastes generated from manufacturing industries are increasing at an alarming rate and it is consistently increasing. One such industrial solid waste is Used Foundry Sand (UFS). On the other hand, fine aggregates involved in the concrete are generally river sand, which is scarce, high cost and excavation of the river sand that promote environmental degradation. So, there is an urge to find some alternative solution to dispose UFS and to limit the use of river sand. In this research work, river sand was partially replaced by UFS. The percentage replacements were 0, 5, 10, 15, 20 and 25 wt% respectively. Experimental investigations were carried out to evaluate the mechanical, durability and micro-structural properties of M20 concrete at the age of 7, 28 and 91 day. XRD (X-ray Diffraction), EDX (Energy Dispersive X-ray) and optical-microscopic imaging analysis were performed to identify the presence of various compounds and micro cracks in the concrete with UFS. Comparative studies on control mix against trial mix were carried out. It was found that compression strength, flexural strength and modulus of elasticity were approximately constant up to 20 wt% UFS and decreased with further addition. Whereas, split tensile strength was increased after 20 wt% addition but it affects the other properties of concrete. The durability test results showed that the resistance of concrete against abrasion and rapid chloride permeability of the concrete mixture containing UFS up to 20 wt% were almost similar to the values of control mix. The findings suggest that UFS can effectively replace river sand. However, it is recommended that the replacement should not exceed 20 wt%. Copyright © 2017. Published by Elsevier Ltd.

  10. Comparisons of Unconsolidated Sediments Analyzed by APXS (MSL-Curiosity) within Gale Crater, Mars: Soils, Sands of the Barchan and Linear Dunes of the Active Bagnold Dune Field, and Ripple-field Sands.

    Science.gov (United States)

    Thompson, L. M.; O'Connell-Cooper, C.; Spray, J. G.; Gellert, R.; Boyd, N. I.; Desouza, E.

    2017-12-01

    The MSL-APXS has analyzed a variety of unconsolidated sediments within the Gale impact crater, including soils, sands from barchan [High, Namib dunes], and linear dunes [Nathan Bridges, Mount Desert dunes], within the active Bagnold dune field, and sands from two smaller ripple fields ("mega-ripples"). The Gale "soils" (unsorted, unconsolidated sediments, ranging from fine-grained particles (including dust) to coarser "pebbly" material [>2 mm]), are, to a large degree, similar to Martian basaltic soils quantified by APXS, at Gusev crater (MER-A_Spirit) and Meridiani Planum (MER-B_Opportunity). Some local contributions are indicated by, for example, the enriched K levels (relative to a martian average basaltic soil [ABS]) within coarser Gale soil samples, and a Cr, Mn, Fe enrichment within finer-grained samples. Sands (grain size 62 µm to 2 mm) of the Bagnold dunes, generally, exhibit elevated Mg and Ni, indicating enrichment from olivine and pyroxene, but depleted S, Cl and Zn, indicating high activity levels and low dust. Compositional differences, related both to position within a dune (i.e., crest versus off-crest sand), and type of dune (linear versus barchan), are identified. Off-crest sands have Na, Al, Si, K, P contents similar to (or slightly depleted, relative to) the ABS, enrichment in Mg, and low dust content, whilst crest sands contain very high Mg and Ni (relative to the ABS), low felsic elemental concentrations and very low dust content. Cr is significantly enriched (and, to a lesser degree, Mn, Fe, Ti) in the off-crest sands of the linear dunes. In contrast, barchan dunes off-crest sands have Cr, Mn, Fe, and Ti abundances similar to those in the Gale soils. Additionally, Ni concentrations in barchan dunes off-crest sands are enriched relative to the linear dunes. Analyses from a small, isolated "mega-ripple" reveal a composition similar to that of the Gale soils, including a high dust content. The second mega-ripple, within a larger ripple field, is

  11. Laboratory evaluation of selected tar sand asphalts

    Energy Technology Data Exchange (ETDEWEB)

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

    1980-12-01

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

  12. Pattern formation - Instabilities in sand ripples

    DEFF Research Database (Denmark)

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

    2001-01-01

    Sand ripples are seen below shallow wavy water and are formed whenever water oscillates over a bed of sand. Here we analyse the instabilities that can upset this perfect patterning when the ripples are subjected to large changes in driving amplitude or frequency, causing them to deform both...... parallel and transverse to their crests. Our results reveal new pattern-forming instabilities in granular matter exposed to fluid flow with strong vorticity....

  13. Supercritical solvent extraction of oil sand bitumen

    Science.gov (United States)

    Imanbayev, Ye. I.; Ongarbayev, Ye. K.; Tileuberdi, Ye.; Mansurov, Z. A.; Golovko, A. K.; Rudyk, S.

    2017-08-01

    The supercritical solvent extraction of bitumen from oil sand studied with organic solvents. The experiments were performed in autoclave reactor at temperature above 255 °C and pressure 29 atm with stirring for 6 h. The reaction resulted in the formation of coke products with mineral part of oil sands. The remaining products separated into SARA fractions. The properties of the obtained products were studied. The supercritical solvent extraction significantly upgraded extracted natural bitumen.

  14. Increased Durability of Concrete Made with Fine Recycled Concrete Aggregates Using Superplasticizers

    OpenAIRE

    Cartuxo, Francisco; de Brito, Jorge; Evangelista, Luis; Jim?nez, Jos? Ram?n; Ledesma, Enrique F.

    2016-01-01

    This paper evaluates the influence of two superplasticizers (SP) on the durability properties of concrete made with fine recycled concrete aggregate (FRCA). For this purpose, three families of concrete were tested: concrete without SP, concrete made with a regular superplasticizer and concrete made with a high-performance superplasticizer. Five volumetric replacement ratios of natural sand by FRCA were tested: 0%, 10%, 30%, 50% and 100%. Two natural gravels were used as coarse aggregates. All...

  15. Fine 5 kolib Kumu lavale

    Index Scriptorium Estoniae

    2006-01-01

    Kumu kunstimuuseumi auditooriumis toimub 21. veebruaril Fine 5 kaasaegse tantsu etendus "Panus". Esinevad Tiina Ollesk, Irina Pähn, žonglöör Dimitri Kruus, disainer Rain Saukas ja muusik Mattias Siitan

  16. Nitramine Drying & Fine Grinding Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Nitramine Drying and Fine Grinding Facility provides TACOM-ARDEC with a state-of-the-art facility capable of drying and grinding high explosives (e.g., RDX and...

  17. Finely divided, irradiated tetrafluorethylene polymers

    International Nuclear Information System (INIS)

    Brown, M.T.; Rodway, W.G.

    1977-01-01

    Dry non-sticky fine lubricant powders are made by γ-irradiation of unsintered coagulated dispersion grade tetrafluoroethylene polymers. These powders may also be dispersed in an organic medium for lubricating purposes

  18. Diamonds, a resource curse? The case of Kono District in Sierra Leone

    Science.gov (United States)

    Wilson, Sigismond Ayodele

    Using an actor-oriented approach to political ecology integrated with theory on the social production of scale, this dissertation examines the extent to which diamond exploitation constitutes a resource curse in Sierra Leone, with Kono District as a case-study. It uses social survey methods and remote sensing analysis of Landsat images to (1) evaluate the role of Sierra Leone's diamonds in economic development from a historical lens, (2) examine the extent to which a weak regulatory state apparatus makes a rich diamond endowment more of a curse than a blessing, (3) determine whether geographically diffuse and remotely-located diamonds are more a liability than an asset, and (4) assess whether environmental conditions are worse in diamond than in non-diamond chiefdoms. Results of the study showed that the contribution of diamonds to national economic growth declined precipitously following the politicization of diamonds and growing informalization of mining under the leadership of Siaka Stevens. Growing disenchantment combined with grievances over access to diamond resources and rights, culminating in a civil war fuelled by conflict diamonds. Findings indicated that actors capitalized on a weak regulatory state to fulfill their agendas. Illicit diamond exploitation was mainly driven by corruption, economic constraints and perverse economic incentives. Preferential land allocation to industrial mining following World Bank Group-directed national mining policy reforms and the weakness of the state in ensuring companies' adherence to mining clauses precipitated corporation-community conflicts. Study findings showed that the resource curse was acute on diggers who received less than 1 a day unlike their South American counterparts who made at least 7 daily. Results from the study demonstrate that the spatiality of diamonds also contributed to the resource curse. Illicit diamond mining was more acute in remotely located mining sites than in extractive sites closer to

  19. The quality of free antenatal and delivery services in Northern Sierra Leone.

    Science.gov (United States)

    Koroma, Manso M; Kamara, Samuel S; Bangura, Evelyn A; Kamara, Mohamed A; Lokossou, Virgil; Keita, Namoudou

    2017-07-12

    The number of maternal deaths in sub-Saharan Africa continues to be overwhelmingly high. In West Africa, Sierra Leone leads the list, with the highest maternal mortality ratio. In 2010, financial barriers were removed as an incentive for more women to use available antenatal, delivery and postnatal services. Few published studies have examined the quality of free antenatal services and access to emergency obstetric care in Sierra Leone. A cross-sectional survey was conducted in 2014 in all 97 peripheral health facilities and three hospitals in Bombali District, Northern Region. One hundred antenatal care providers were interviewed, 276 observations were made and 486 pregnant women were interviewed. We assessed the adequacy of antenatal and delivery services provided using national standards. The distance was calculated between each facility providing delivery services and the nearest comprehensive emergency obstetric care (CEOC) facility, and the proportion of facilities in a chiefdom within 15 km of each CEOC facility was also calculated. A thematic map was developed to show inequities. The quality of services was poor. Based on national standards, only 27% of women were examined, 2% were screened on their first antenatal visit and 47% received interventions as recommended. Although 94% of facilities provided delivery services, a minority had delivery rooms (40%), delivery kits (42%) or portable water (46%). Skilled attendants supervised 35% of deliveries, and in only 35% of these were processes adequately documented. None of the five basic emergency obstetric care facilities were fully compliant with national standards, and the central and northernmost parts of the district had the least access to comprehensive emergency obstetric care. The health sector needs to monitor the quality of antenatal interventions in addition to measuring coverage. The quality of delivery services is compromised by poor infrastructure, inadequate skilled staff, stock-outs of

  20. Layers, Landslides, and Sand Dunes

    Science.gov (United States)

    2003-01-01

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

  1. Changes in algal stable isotopes following nutrient and peat amendments in oil sands aquatic reclamation

    Energy Technology Data Exchange (ETDEWEB)

    Farwell, A.; Chen, H.; Boutsivongskad, M.; Dixon, D. [Waterloo Univ., ON (Canada)

    2010-07-01

    The processing of oil sands in Alberta generates large volumes of processed material that must be reclaimed. Processed water and solids (PW/S) contain higher levels of naturally occurring compounds such as naphthenic acids (NAs) and polycyclic aromatic compounds (PACs). Organic carbon and nitrogen are some of the constituents in PW/S that may provide nutrient sources for aquatic reclamation sites as they develop into viable ecosystems. This study was conducted to assess the modifying factors that may affect the stable carbon and nitrogen isotope values of primary production in oil sands aquatic reclamation. Both field-based microcosm studies and laboratory studies were used to evaluate the changes in the growth and stable isotope values of phytoplankton, periphyton and/or filamentous algae along gradients of dissolved organic carbon (DOC), dissolved inorganic carbon (DIC), nitrogen and phosphorus. Various types of reclamation substrates were used in the study, including various combinations of sand, mature fine tailings, peat and process water. Results showed different levels of growth depending on both the water and substrate type. Typically, periphyton from oil sands reclamation sites were more enriched in 15N than the reference site. Periphyton from one site known as the MP site was more enriched in 13C than periphyton from another site know as the Shallow Wetland South Ditch (SWSD). However, periphyton in the demonstration pond (DP) was more 13C depleted than the reference site. Findings from this study indicate that carbon isotopes are influenced by other factors, such as nutrients.

  2. Process water treatment in Canada's oil sands industry : 2 : a review of emerging technologies

    International Nuclear Information System (INIS)

    Allen, E.W.

    2008-01-01

    This review was conducted to identify candidate treatment technologies for treating oil sands process water. The oil sands industry in Canada uses large volumes of fresh water in order to extract bitumen deposits. The development of process water treatment technologies has become a critical issue for the industry, particularly as oil sand production is expected to triple in the next decade. However, treatment technologies must be adapted to consider the fouling potential of bitumens and fine clays as well as the effect of alkaline process water on treatment performance. The review included developments in chemical modifications to membranes and adsorbents designed to improve pollutant removal and reduce fouling; hybridization technologies designed to enhance the biological treatment of toxic feedwaters; recent advances in photocatalytic oxidation technologies for organic compounds; and new designs for large-scale treatment wetlands for polluted waste waters. It was concluded that major knowledge gaps must be optimized and preliminary studies must be conducted in order to understand how the treatment technologies will be affected by the chemical and physical characteristics of oil sands process water. 188 refs., 8 tabs

  3. Changes in algal stable isotopes following nutrient and peat amendments in oil sands aquatic reclamation

    International Nuclear Information System (INIS)

    Farwell, A.; Chen, H.; Boutsivongskad, M.; Dixon, D.

    2010-01-01

    The processing of oil sands in Alberta generates large volumes of processed material that must be reclaimed. Processed water and solids (PW/S) contain higher levels of naturally occurring compounds such as naphthenic acids (NAs) and polycyclic aromatic compounds (PACs). Organic carbon and nitrogen are some of the constituents in PW/S that may provide nutrient sources for aquatic reclamation sites as they develop into viable ecosystems. This study was conducted to assess the modifying factors that may affect the stable carbon and nitrogen isotope values of primary production in oil sands aquatic reclamation. Both field-based microcosm studies and laboratory studies were used to evaluate the changes in the growth and stable isotope values of phytoplankton, periphyton and/or filamentous algae along gradients of dissolved organic carbon (DOC), dissolved inorganic carbon (DIC), nitrogen and phosphorus. Various types of reclamation substrates were used in the study, including various combinations of sand, mature fine tailings, peat and process water. Results showed different levels of growth depending on both the water and substrate type. Typically, periphyton from oil sands reclamation sites were more enriched in 15N than the reference site. Periphyton from one site known as the MP site was more enriched in 13C than periphyton from another site know as the Shallow Wetland South Ditch (SWSD). However, periphyton in the demonstration pond (DP) was more 13C depleted than the reference site. Findings from this study indicate that carbon isotopes are influenced by other factors, such as nutrients.

  4. Provenance and recycling of Arabian desert sand

    Science.gov (United States)

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

    2013-05-01

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

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

    International Nuclear Information System (INIS)

    Heuvel, M.R. van den; Dixon, D.G.; Power, M.; Boerger, H.; MacKinnon, M.D.; Meer, T. van

    1995-01-01

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

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

    NARCIS (Netherlands)

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

    2010-01-01

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

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

    NARCIS (Netherlands)

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

    2010-01-01

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

  8. Effect of flow rate on stability of unconsolidated producing sands

    Energy Technology Data Exchange (ETDEWEB)

    Tippie, D.B.; Kohlhaas, C.A.

    1973-01-01

    Stabilization of unconsolidated sand during production by sand arching was confirmed with a sandpack model of a well completion. Fluid was flowed radially through a sand pack which was loaded vertically to simulate overburden pressure. Flow rates were gradually increased to the point at which sand flowed and the arch then examined. Larger arches resulted from higher flow rates. Critical rate for the sand production depended on rate history as well as rate magnitude and arch size.

  9. Nise da Silveira, Fernando Diniz e Leon Hirszman: política, sociedade e arte

    Directory of Open Access Journals (Sweden)

    Walter Melo

    2010-09-01

    Full Text Available O presente artigo aborda o processo de construção do filme Imagens do Inconsciente, mais especificamente do episódio Em Busca do Espaço Cotidiano, sobre Fernando Diniz e sua produção pictórica. O encontro entre a psiquiatra Nise da Silveira e o cineasta Leon Hirszman está marcado pela não dissociação de política, sociedade e arte. O trabalho terapêutico e de reabilitação psicossocial desenvolvido por Nise da Silveira tem como característica o estabelecimento de importantes conexões com o campo das artes, possibilitando o diálogo com toda a sociedade. Esse trabalho de transformação cultural e de mentalidades fez com que fosse questionada a exclusão social dos chamados doentes mentais e transformada a política de assistência no campo da saúde mental no Brasil.

  10. Social pathways for Ebola virus disease in rural Sierra Leone, and some implications for containment.

    Directory of Open Access Journals (Sweden)

    Paul Richards

    2015-04-01

    Full Text Available The current outbreak of Ebola Virus Disease in Upper West Africa is the largest ever recorded. Molecular evidence suggests spread has been almost exclusively through human-to-human contact. Social factors are thus clearly important to understand the epidemic and ways in which it might be stopped, but these factors have so far been little analyzed. The present paper focuses on Sierra Leone, and provides cross sectional data on the least understood part of the epidemic-the largely undocumented spread of Ebola in rural areas. Various forms of social networking in rural communities and their relevance for understanding pathways of transmission are described. Particular attention is paid to the relationship between marriage, funerals and land tenure. Funerals are known to be a high-risk factor for infection. It is suggested that more than a shift in awareness of risks will be needed to change local patterns of behavior, especially in regard to funerals, since these are central to the consolidation of community ties. A concluding discussion relates the information presented to plans for halting the disease. Local consultation and access are seen as major challenges to be addressed.

  11. Soil Properties Database of Spanish Soils. Volume XII.- Castilla-Leon (c): Burgos, Soria and Segovia

    International Nuclear Information System (INIS)

    Trueba, C; Millan, R.; Schmid, T.; Lago, C.; Roquero, C; Magister, M.

    1999-01-01

    The soil vulnerability determines the sensitivity of the soil after an accidental radioactive contamination due to Cs-137 and Sr-90. The Departamento de Impacto Ambiental de la Energia of CIEMAT is carrying out an assessment of the radiological vulnerability of the different Spanish soils found on the Iberian Peninsula. This requires the knowledge of the soil properties for the various types of existing soils. In order to achieve this aim, a bibliographical compilation of soil profiles has been made to characterize the different soil types and create a database of their properties. Depending on the year of publication and the type of documentary source, the information compiled from the available bibliography is very heterogeneous. Therefore, an important effort has been made to normalize and process the information prior to its incorporation to the database. This volume presents the criteria applied to normalize and process the data as well as the soil properties of the various soil types belonging to the provinces of Burgos, Soria and Segovia of the Comunidad Autonoma de Castilla-Leon. (Author) 36 refs

  12. Morphological characterization of lentil (lens culinaris medik.) landraces from castilla y leon, spain

    International Nuclear Information System (INIS)

    Aslam, K.; Arif, M.

    2014-01-01

    The characterization of plant genetic resources has a significant impact on their possible future use in lentil breeding programs and also, in the activity of germplasm collections. In this work we have characterized 27 lentil landraces from the region of Castilla and Leon (plateau in Northern Spain), existing among them two different morphological groups according to the characteristics of the seeds (Macrosperma and Microsperma). Fifteen morpho-agronomical characters were measured for data collection. A principal components analysis allowed the definition of the 5 factors which explain 83.7% of the cumulative variance. The first factor explains 25.3% of total variation and it is related to seed production. We performed a cluster analysis obtaining 5 groups, each one defined by the average values of the employed characters. 37.0% of landraces were included in group 5, characterized by a high mean of the harvest index (38.4) and also a high mean value (74.4) for the number of pods. To study the seeds we used a correspondence analysis 6 dimensions which explained the 80.9% of the variance were chosen. Two cluster analysis were carried out using the coordinates of the aforementioned analysis. The aim of this work was to study the morphological variability of these populations and to discover the relationship among them. (author)

  13. Short Report: Serological Evidence of Under-Reported Dengue Circulation in Sierra Leone.

    Directory of Open Access Journals (Sweden)

    Jaime M de Araújo Lobo

    2016-04-01

    Full Text Available Dengue virus (DENV is thought to have emerged from a sylvatic cycle in Africa but has since become adapted to an urban-centric transmission cycle. These urban areas include villages in West Africa where DENV is not often routinely considered for patients presenting with febrile illnesses, as other endemic diseases (malaria, Lassa fever, e.g. present with similar non-specific symptoms. Thus, dengue is likely under diagnosed in the region. These plaque reduction neutralization test-50 (PRNT50 screening results of patients presenting with fevers of unknown origin (FUO at a clinic in Kenema, Sierra Leone indicate that all four serotypes of DENV likely circulate in areas surrounding Kenema. Using a more conservative PRNT80 cut-off value, our results still indicate the presence of antibody to all four serotypes in the region. Identifying alternate etiologies of FUOs in this region will assist clinicians in plan-of-care decisions as well as follow-up priorities. This is particularly relevant given the Ebola outbreak in the region, where diagnosis has a range of downstream effects ranging from correct allocation of medical resources, appropriate isolation of patients, and ultimately, a better informed public health sector.

  14. Measuring work engagement among community health workers in Sierra Leone: Validating the Utrecht Work Engagement Scale

    Directory of Open Access Journals (Sweden)

    Frédérique Vallières

    2017-04-01

    Full Text Available This study examines the concept of volunteer work engagement in a sample of 334 community health workers in Bonthe District, Sierra Leone. Structural equation modelling was used to validate both the 9-item and the 17-item Utrecht Work Engagement Scale (UWES-9 and UWES-17, respectively. Results assessing the UWES-17 invalidated the three-factor structure within this cohort of community health workers, as high correlations were found between latent factors. Findings for the validity of the UWES-9 were largely consistent with those of the UWES-17. Model fit for the UWES-9 were generally equivalent for the one-factor, three-factor, and bifactor solutions, however the three-factor model was once again rejected due to high factor correlations. Based on these results, the current sample provides evidence that work engagement is best represented as a unidimensional construct in this context. Findings are considered alongside previous research to offer support for the utilization of the shortened UWES-9 in this context, as it appears to provide a good representation of work engagement and possess a parsimonious unidimensional scoring scheme.

  15. Diamonds and development: A critical analysis of stereotypes about mineworkers in Sierra Leone

    Directory of Open Access Journals (Sweden)

    Lorenzo D’Angelo

    2015-06-01

    Full Text Available In the last decade, the Sierra Leone’s diamond mines have been the focus of an intense debate among analysts and experts of the development. Two main interrelated issues have been at stake in this debate: first, to understand the economic and political reasons that had supported the civil war from 1991 to 2002 and, second, to understand how to convert a potential “conflict commodity” in a resource for peace and prosperity. In this paper, I intend to highlight some recurring stereotypes of this debate. In particular, I will focus on a constellation of representations that depict the artisanal miners either as workers poorly organized and prone to irrational economic behavior, or as workers subjected to forms of exploitation akin to slavery. Based on fieldwork conducted in the diamond mining areas of Sierra Leone (2007-2011, this article intends to analyze the main forms of working organization and distribution of earnings among the miners. By challenging some stereotypes characterizing the development discourse, my aim is to show the cultural complexity and the historical density of the practices through which the miners face the risks and uncertainties of their job.

  16. Sequelae and Other Conditions in Ebola Virus Disease Survivors, Sierra Leone, 2015.

    Science.gov (United States)

    Mohammed, Hamish; Vandy, Alren O; Stretch, Rebecca; Otieno, David; Prajapati, Mukesh; Calderon, Mauricio; Vandi, Mohamed

    2017-01-01

    We rapidly assessed the health of Ebola virus disease (EVD) survivors in Kenema, Sierra Leone, by reviewing medical charts of all patients attending the Survivor Clinic of Kenema Government Hospital. Data were abstracted on signs and symptoms at every attendance. As of November 2015, a total of 621 attendances by 115 survivors with laboratory-confirmed EVD were made to the Survivor Clinic. Most (60.9%) survivors were women. Survivors' median age was 28 years (range 0.25-70 years). Survivors attended the clinic a median of 5 times (range 1-21 times) each, and the median time from EVD discharge to attendance was 261 days (range 4-504 days). The most commonly reported signs and symptoms among the 621 attendances were headache (63.1%), fever (61.7%), and myalgia (43.3%). Because health needs of EVD survivors are complex, rapid chart reviews at survivor clinics should be repeated regularly to assess the extent of illness and prioritize service delivery.

  17. The etiology of Ebola virus disease-like illnesses in Ebola virusnegative patients from Sierra Leone.

    Science.gov (United States)

    Li, Wen-Gang; Chen, Wei-Wei; Li, Lei; Ji, Dong; Ji, Ying-Jie; Li, Chen; Gao, Xu-Dong; Wang, Li-Fu; Zhao, Min; Duan, Xue-Zhang; Duan, Hui-Juan

    2016-05-10

    During the 2014 Ebola virus disease (EVD) outbreak, less than half of EVD-suspected cases were laboratory tested as Ebola virus (EBOV)-negative, but disease identity remained unknown. In this study we investigated the etiology of EVD-like illnesses in EBOV-negative cases. From November 13, 2014 to March 16, 2015, EVD-suspected patients were admitted to Jui Government Hospital and assessed for EBOV infection by real-time PCR. Of 278 EBOV negative patients, 223 (80.21%), 142 (51.08%), 123 (44.24%), 114 (41.01%), 59 (21.22%), 35 (12.59%), and 12 (4.32%) reported fever, headache, joint pain, fatigue, nausea/vomiting, diarrhea, hemorrhage, respectively. Furthermore, 121 (43.52%), 44 (15.83%), 36 (12.95%), 33 (11.87%), 23 (8.27%), 10 (3.60%) patients were diagnosed as infection with malaria, HIV, Lassa fever, tuberculosis, yellow fever, and pneumonia, respectively. No significant differences in clinical features and symptoms were found between non-EVD and EVD patients. To the best of our knowledge, the present study is the first to explore the etiology of EVD-like illnesses in uninfected patients in Sierra Leone, highlighting the importance of accurate diagnosis to EVD confirmation.

  18. Changing Patterns of Health in Communities Impacted by a Bioenergy Project in Northern Sierra Leone

    Science.gov (United States)

    Knoblauch, Astrid M.; Hodges, Mary H.; Bah, Mohamed S.; Kamara, Habib I.; Kargbo, Anita; Paye, Jusufu; Turay, Hamid; Nyorkor, Emmanuel D.; Divall, Mark J.; Zhang, Yaobi; Utzinger, Jürg; Winkler, Mirko S.

    2014-01-01

    Large private sector investments in low- and middle-income countries are often critically evaluated with regards to their environmental, social, human rights, and health impacts. A health impact assessment, including a baseline health survey, was commissioned by the Addax Bioenergy Sierra Leone project in 2010. As part of the monitoring, a follow-up survey was conducted three years later. A set of health indicators was assessed at six impacted and two control sites. Most of these indices improved, particularly at the impacted sites. The prevalences of stunting, wasting, and Plasmodium falciparum in children under five years of age decreased significantly at impacted sites (all p < 0.05) and non-significantly at control sites. Anemia in children and in women of reproductive age (15–49 years) decreased significantly at impacted and control sites (p < 0.05 and p < 0.001, respectively). Health facility-based deliveries increased significantly at the impacted sites (p < 0.05). The prevalences of helminth infections in children aged 10–15 years remained approximately at the same levels, although focal increases at the impacted sites were noted. Access to improved sanitation decreased significantly (p < 0.05) at control and non-significantly at impacted sites. Water quality remained poor without significant changes. The epidemiologic monitoring of a bioenergy project provides a useful contribution for evidence-based decision-making. PMID:25514152

  19. Synoptic patterns associated with wildfires caused by lightning in Castile and Leon, Spain

    Directory of Open Access Journals (Sweden)

    E. García-Ortega

    2011-03-01

    Full Text Available The Iberian Peninsula presents the highest number of wildfires in Europe. In the NW of Spain in particular, wildfires are the natural risk with the greatest economic impact in this region. Wildfires caused by lightning are closely related to the triggering of convective phenomena. The prediction of thunderstorms is a very complex task because these weather events have a local character and are highly dependent on mesoscale atmospheric conditions. The development of convective storms is directly linked to the existence of a synoptic environment favoring convection. The aim of this study is to classify the atmospheric patterns that provide favorable environments for the occurrence of wildfires caused by lightning in the region of Castile and Leon, Spain. The database used for the study contains 376 wildfire days from the period 1987–2006. NCEP data reanalysis has been used. The atmospheric fields used to characterise each day were: geopotential heights and temperatures at 500 hPa and 850 hPa, relative humidity and the horizontal wind at 850 hPa. A Principal Component Analysis in T-mode followed by a Cluster Analysis resulted in a classification of wildfire days into five clusters. The characteristics of these clusters were analysed and described, focusing particularly on the study of those wildfire days in which more than one wildfire was detected. In these cases the main feature observed was the intensification of the disturbance typical of the cluster to which the wildfire belongs.

  20. Updated comparison of groundwater flow model results and isotopic data in the Leon Valley, Mexico

    Science.gov (United States)

    Hernandez-Garcia, G. D.

    2015-12-01

    Northwest of Mexico City, the study area is located in the State of Guanajuato. Leon Valley has covered with groundwater its demand of water, estimated in 20.6 cubic meters per second. The constant increase of population and economic activities in the region, mainly in cities and automobile factories, has also a constant growth in water needs. Related extraction rate has produced an average decrease of approximately 1.0 m per year over the past two decades. This suggests that the present management of the groundwater should be checked. Management of groundwater in the study area involves the possibility of producing environmental impacts by extraction. This vital resource under stress becomes necessary studying its hydrogeological functioning to achieve scientific management of groundwater in the Valley. This research was based on the analysis and integration of existing information and the field generated by the authors. On the base of updated concepts like the geological structure of the area, the hydraulic parameters and the composition of deuterium-delta and delta-oxygen -18, this research has new results. This information has been fully analyzed by applying a groundwater flow model with particle tracking: the result has also a similar result in terms of travel time and paths derived from isotopic data.

  1. Soil Properties Database of Spanish Soils. Volume XI.- Castilla-Leon (b): Palencia, Valladolid and Avila

    International Nuclear Information System (INIS)

    Trueba, C; Millan, R.; Schmid, T.; Lago, C.; Roquero, C; Magister, M.

    1999-01-01

    The soil vulnerability determines the sensitivity of the soil after an accidental radioactive contamination due to Cs-137 and Sr-90. The Departamento de Impacto Ambiental de la Energia of CIEMAT is carrying out an assessment of the radiological vulnerability of the different Spanish soils found on the Iberian Peninsula. This requires the knowledge of the soil properties for the various types of existing soils. In order to achieve this aim, a bibliographical compilation of soil profiles has been made to characterize the different soil types and create a database of their properties. Depending on the year of publication and the type of documentary source, the information compiled from the available bibliography is very heterogeneous. Therefore, an important effort has been made to normalize and process the information prior to its incorporation to the database. This volume presents the criteria applied to normalize and process the data as well as the soil properties of the various soil types belonging to the provinces of Palencia. Valladolid and Avila of the Comunidad Autonoma de Castilla-Leon. (Author) 41 refs

  2. Health-hazard evaluation report HETA 83-156-1622, Leon Plastics, Grand Rapids, Michigan

    Energy Technology Data Exchange (ETDEWEB)

    Ahrenholz, S.H.; Anderson, K.E.

    1985-09-01

    Environmental and breathing-zone samples were analyzed for azodicarbonamide, benzene, styrene, and toluene at Leon Plastics, Grand Rapid, Michigan in March and May 1983, and March 1984. The evaluation was requested to investigate occupational exposures to chemical agents, particularly in the injection molding department. Sixteen employees were interviewed. Azodicarbonamide concentrations ranged from undetectable to 280 micrograms per cubic meter (microg/m/sup 3/) in May 1983, and from undetectable to 752 microg/m/sup 3/ in March 1984. There is no federal standard for azodicarbonamide. The concentrations of the other substances were below their relevant standards. Ammonia, styrene, and triphenylphosphate were identified as pyrolysis products above the azodicarbonamide presses. Symptoms of eye, nose and throat irritation, coughing, and wheezing were reported. Pulmonary-function test results could not be linked to azodicarbonamide exposures. The authors conclude that exposure to azodicarbonamide is the probable cause of the reported symptoms. Recommendations include using engineering controls and appropriate work practices to minimize exposure to azodicarbonamide.

  3. Improvement of Dune Sands by Residual Oil in Order to Use in Construction of Lagoons

    Directory of Open Access Journals (Sweden)

    Alborz Hajian nia

    2011-10-01

    Full Text Available This research which is based on experimental work, devoted to study the improvement and stabilization of dune sands in order to create strong layer and stabilize slope and floor construction of sewage Lagoons. Materials used stabilizing these soils are residual oil from the refinery. To confirm the effectiveness of the use of residual oil to improve the mechanical properties of the sand, various samples with different percentages were tested. In besides, the geotechnical and environmental tests were done. Results demonstrate that samples made with 5% oil have highest shear and unconfined compaction strength. It revealed that in compare with natural samples, cohesion and loading capacity highly increased and permeability decrease well. Percentage of fine aggregate, minerals and durability of oil in soil material were also investigated. Finally, effects of sewage on the samples were analyzed, and performance the oils were evaluated in order to use in lagoons.

  4. Nuclear energy in the oils sands

    International Nuclear Information System (INIS)

    Arsenault, J.E.

    2014-01-01

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

  5. The Effect of use the Silica Sand

    Directory of Open Access Journals (Sweden)

    Nahla N. Helal

    2013-04-01

    Full Text Available This research includes study the effects of use the silica sand at different rates and comparison some characteristics with other concrete mixture contains ordinary sand to investigate the effect on some mechanical properties of concrete such as compressive strength, density absorption and flexural strength after (3, 7, 14 and 28 days for four mixtures.  , the ordinary sand was replaced by the (Silica Sand at different rates ( 25%, 50%, 75%, 100%. Sodium Silicate solution at percentage of cement ratio(water to cement ratio is decreased on same ratio added to the Ideal silica sand mixture  to study the effect of addition of some additives on concrete. The study showed that the  best results of mixture was when  replaced (75% of the ordinary sand by silica sand , then study some mechanical properties of mixtures such as compressive strength, density absorption and flexural strength after (3, 7, 14 and 28 days .                             The study showed the optimum percentage of sodium silicate was (1.75%. The study showed that the best result of Density was (2493Kg/m3 after (28 days, and the increment ratio in Density was (2.95%, and the large value in compressive strength was (85.76 MPa which was (42.9% after (28 days. The study showed also that the best results of absorption were (0.77 after (28 days, and the decrement ratio in Absorption was (33.8%. The study showed that the best result of flexural strength was (8.02 MPa after (28 days, and the maximum increment ratio in Flexural Strength was (150.6% after (28 days.

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

    Science.gov (United States)

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

    2009-01-01

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

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

    Science.gov (United States)

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

    2010-02-01

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

  8. La villa de Benavente y su tierra a fines del siglo XV y durante la primera mitad del siglo XVI

    Directory of Open Access Journals (Sweden)

    Severiano HERNÁNDEZ

    2009-12-01

    Full Text Available El estudio de los núcleos urbanos se ha constituido como una de las cuestiones clave de la formación social feudal y ello en un entorno social con un marcado cariz rural, en el que la tierra aparece como una realidad omnipresente. En relación con estos planteamientos —indicios de una problemática amplia y sugestiva— el objetivo del presente artículo es, únicamente, el de acercarnos al conocimiento general de algunos aspectos de la organización y de la vida cotidiana de un concejo castellano-leonés de señorío: el concejo de Benavente a fines del siglo XV y durante los primeros años del siglo XVI.

  9. Determination of the equivalent intergranular void ratio - Application to the instability and the critical state of silty sand

    Directory of Open Access Journals (Sweden)

    Nguyen Trung-Kien

    2017-01-01

    Full Text Available This paper presents an experimental study of mechanical response of natural Camargue silty sand. The analysis of test results used the equivalent intergranular void ratio instead of the global void ratio. The calculation of equivalent intergranular void ratio requires the determination of parameter b which represents, physically, the fraction of active fines participating on the chain forces network, hence the strength of the soil. A new formula for determining the parameter b by using an approach based on the coordination number distribution and probability calculation is proposed. The validation of the developed relationship was done through back-analysis of published datasets in literature on the effect of fines content on silty sand behavior. It is shown that the equivalent intergranular void ratio calculated with the b value obtained by the new formula is able to provide strong correlation to not only the critical state of but also the onset of instability of various silty sands, in different terms as peak deviator stress, peak stress ratio or cyclic resistance. Therefore, it is suggested that the use of the equivalent void ratio concept and the new b calculating formula is highly desirable in predicting of the silty sand behavior.

  10. Studies of sand drift by neutron activation analysis of trace elements in natural sand

    International Nuclear Information System (INIS)

    Ma, J.; Chai, Z.; Ma, S.; Mao, X.; Qian, Q.; Mao, Z.; Yan, P.

    1991-01-01

    On the basis of the inhomogeneous distribution of trace elements in nature and essential characteristics of the sand drift, the authors have proposed a so-called mix-model of trace elements as a law of the sand drift, and developed a few calculation methods to determine the drift directions, possible sources as well as their contributions to the sand. Using neutron activation analysis method for determining the concentrations of the trace elements in natural sand samples from different sources, they have investigated three areas, the Shantou Harbor, the Shanghai Harbor and a section of the Great Canal of China, to decipher the movement and sedimentation tendency of the sands there. Their results agree with those by conventional measurement methods in water conservancy works, and their method has provided some obvious advantages of time-saving, cost-saving, sampling without restriction of time and ease to be implemented

  11. Making of polymer fine particles

    International Nuclear Information System (INIS)

    Ono, Isamu

    1990-01-01

    The polymer particles having spherical shape and uniform grain diameter are applied to various fields such as powder coating, cosmetics, medicines, foods and others. These polymer fine particles are synthesized from monomers at the temperature higher than room temperature by emulsifying polymerization, suspension polymerization or dispersion polymerization, using polymerization initiator. The diameter of such synthesized fine particles is from 0.1 to 10 μm. In this study, the method of synthesizing polymer fine particles by dispersion radiation polymerization process without using polymerization initiator and emulsifying agent was examined. Monomers are dissolved in the solvent, in which monomers are soluble but polymers are insoluble, and by polymerizing with radiation, polymer fine particles are synthesized. It has the merits that additive agents are not contained, and the synthesis can be done at room temperature. The method and the results are reported. As the mechanism of forming fine particles, the reaction of beginning polymerization and the precipitation of polymers are explained. By controlling reaction temperature and monomer concentration, particle diameter can be adjusted. The monomers used were styrene, methyl metacrylate and vinyl acetate. (K.I.)

  12. Occurrence and concentrations of selected trace elements and halogenated organic compounds in stream sediments and potential sources of polychlorinated biphenyls, Leon Creek, San Antonio, Texas, 2012–14

    Science.gov (United States)

    Wilson, Jennifer T.

    2016-06-23

    The Texas Department of State Health Services issued fish consumption advisories in 2003 and 2010 for Leon Creek in San Antonio, Texas, based on elevated concentrations of polychlorinated biphenyls (PCBs) in fish tissues. The U.S. Geological Survey (USGS) measured elevated PCB concentrations in stream-sediment samples collected during 2007–9 from Leon Creek at Lackland Air Force Base (now known as Joint Base San Antonio-Lackland; the sampling site at this base is hereinafter referred to as the “Joint Base site”) and sites on Leon Creek downstream from the base. This report describes the occurrence and concentrations of selected trace elements and halogenated organic compounds (pesticides, flame retardants, and PCBs) and potential sources of PCBs in stream-sediment samples collected from four sites on Leon Creek during 2012–14. In downstream order, sediment samples were collected from Leon Creek at northwest Interstate Highway 410 (Loop 410), Rodriguez Park, Morey Road, and Joint Base. The USGS periodically collected streambed-sediment samples during low flow and suspended-sediment samples during high flow.

  13. A Improved Seabed Surface Sand Sampling Device

    Science.gov (United States)

    Luo, X.

    2017-12-01

    In marine geology research it is necessary to obtain a suf fcient quantity of seabed surface samples, while also en- suring that the samples are in their original state. Currently,there are a number of seabed surface sampling devices available, but we fnd it is very diffcult to obtain sand samples using these devices, particularly when dealing with fne sand. Machine-controlled seabed surface sampling devices are also available, but generally unable to dive into deeper regions of water. To obtain larger quantities of seabed surface sand samples in their original states, many researchers have tried to improve upon sampling devices,but these efforts have generally produced ambiguous results, in our opinion.To resolve this issue, we have designed an improved andhighly effective seabed surface sand sampling device that incorporates the strengths of a variety of sampling devices. It is capable of diving into deepwater to obtain fne sand samples and is also suited for use in streams, rivers, lakes and seas with varying levels of depth (up to 100 m). This device can be used for geological mapping, underwater prospecting, geological engineering and ecological, environmental studies in both marine and terrestrial waters.

  14. Capturing phosphates with iron enhanced sand filtration.

    Science.gov (United States)

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

    2012-06-01

    Most treatment practices for urban runoff capture pollutants such as phosphorus by either settling or filtration while dissolved phosphorus, typically as phosphates, is untreated. Dissolved phosphorus, however, represents an average 45% of total phosphorus in stormwater runoff and can be more than 95%. In this study, a new stormwater treatment technology to capture phosphate, called the Minnesota Filter, is introduced. The filter comprises iron filings mixed with sand and is tested for phosphate removal from synthetic stormwater. Results indicate that sand mixed with 5% iron filings captures an average of 88% phosphate for at least 200 m of treated depth, which is significantly greater than a sand filter without iron filings. Neither incorporation of iron filings into a sand filter nor capture of phosphates onto iron filings in column experiments had a significant effect on the hydraulic conductivity of the filter at mixtures of 5% or less iron by weight. Field applications with up to 10.7% iron were operated over 1 year without detrimental effects upon hydraulic conductivity. A model is applied and fit to column studies to predict the field performance of iron-enhanced sand filters. The model predictions are verified through the predicted performance of the filters in removing phosphates in field applications. Practical applications of the technology, both existing and proposed, are presented so stormwater managers can begin implementation. Copyright © 2012 Elsevier Ltd. All rights reserved.

  15. The behavior of gaseous iodine in sand

    International Nuclear Information System (INIS)

    Takahashi, Kanji

    1974-01-01

    Radioactive iodine gas was passed through 10 different sands collected at rivers and hills. The relation between the amount of the loaded gas and the amount of adsorbed gas was determined at room temperature, 50 -- 60 0 C, and 90 -- 100 0 C under humidity of 2 sand. This amount was about 1 -- 3 times as much as that of monomolecular membrane adsorption, 0.2 -- 0.3 μg/cm 2 . The decrease of adsorption amount that accompanies the increase of humidity is attributable to the decrease of effective surface area of sand due to the presence of water. The transport of iodine in sand was studied by passing gaseous iodine through a glass tubing packed with sand. The distribution in the flow direction of iodine indicated that the ease of desorption depends upon the situation of adsorption. Easily desorbed case was named Henry type adsorption. Hardly desorbed case was named absorption type. Discussion is made on experimental results. (Fukutomi, T.)

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

    Science.gov (United States)

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

    2017-12-01

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

  17. The care of fine books

    CERN Document Server

    Greenfield, Jane; Basbanes, Nicholas A

    2014-01-01

    The Care of Fine Books is a thorough, readable guide to caring for books of value. From a discussion of the various techniques and materials used in bookbinding to advice on handling and storage, Jane Greenfield has created a succinct yet complete resource for anyone who wants to preserve and protect their fine books. Whether you are a collector, a librarian, or a conservation professional, you will benefit from this expert advice. Learn about appropriate levels of light, temperature, relative humidity, and pollution; how to secure a collection against fire, insect infestation, flood, and theft; and methods for cleaning and repairing books that have already been damaged. Always practical and amply illustrated, this is a must-have reference for anyone who loves fine books.

  18. A Preliminary Experimental Investigation of Wet Fine Erosion in Two-Phase Flow

    Science.gov (United States)

    Ya, H. H.; luthfi, Haziq; ngo, Nguyet-tran; Hassan, Suhaimi; pao, William

    2018-03-01

    Solid particles below 62 μm is classified as fine. In oil producing operation, the most commonly used downhole sand screen can only capture solid particles of 140 μm and above. Most predictive erosion model is limited to particle size of 100 μm with single phase flow assumption because it is commonly believed that erosion due to particles below 100 μm is insignificant and typically ignored by oil and gas consultants when proposing facilities design. The objective of this paper is to investigate the impact of fines particle on mild steel plate in two-phase flow at different collision angles. A two phase flow loop was set up. The average size of fine particle was 60 μm, mixed with water with sand to water ratio at 1:65 wt/wt. The mild steel plates were oriented at three different impact angles which are -30°, 30° and 90°, with respect to the horizon. Scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), surface roughness and Vickers micro hardness techniques were used to quantify the effects of fine particle on the exposed surface.

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

    Energy Technology Data Exchange (ETDEWEB)

    Schreckengost, D.; Arnold, D.

    1984-09-01

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

  20. Comparision of Fine Needle Aspiration Cytology and Fine Needle ...

    African Journals Online (AJOL)

    Background: Open biopsy of the breast used to be the main traditional method of diagnosis of breast lumps. Fine Needle Aspiration Cytology (FNAC) was later introduced which depends on suction and thus yields hemorrhagic material for cytological study.This study was undertaken to find out if there is a difference in ...

  1. Bioaugmentation of flow-through sand filters

    DEFF Research Database (Denmark)

    Samuelsen, Elin Djurhuus

    filters with specific degrading bacteria. However, degradation efficiency is often hampered by poor adhesion and a lack of sustained catabolic activity of the introduced bacteria. The overall objective of this thesis was to investigate the significance of selected bacterial surface properties...... for degradation performances in flow-through sand columns, with the aim of identifying a suitable inoculant strain for future environmental applications. Another aim was to identify a suitable genetic marker to monitor phenoxy acid degradation in strain Sphingobium sp. PM2. We were not able to link motility...... and biofilm formation to the strains´ ability to adhere to sand. Nevertheless, a correlation was found between cell surface hydrophobicity and adhesion and overall degradation performances in flow-through sand columns. We identified S phingobium sp. PM2 as a promising inoculant strain, displaying efficient...

  2. Planet-wide sand motion on mars

    Science.gov (United States)

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

    2012-01-01

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

  3. 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.

  4. Thermoluminescent dosimetric properties of Descalvado sand

    International Nuclear Information System (INIS)

    Teixeira, M.I.; Caldas, L.V.E.

    2006-01-01

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

  5. Thermoluminescent dosimetric properties of Descalvado sand

    Energy Technology Data Exchange (ETDEWEB)

    Teixeira, M.I.; Caldas, L.V.E

    2006-07-01

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

  6. A Threshold Continuum for Aeolian Sand Transport

    Science.gov (United States)

    Swann, C.; Ewing, R. C.; Sherman, D. J.

    2015-12-01

    The threshold of motion for aeolian sand transport marks the initial entrainment of sand particles by the force of the wind. This is typically defined and modeled as a singular wind speed for a given grain size and is based on field and laboratory experimental data. However, the definition of threshold varies significantly between these empirical models, largely because the definition is based on visual-observations of initial grain movement. For example, in his seminal experiments, Bagnold defined threshold of motion when he observed that 100% of the bed was in motion. Others have used 50% and lesser values. Differences in threshold models, in turn, result is large errors in predicting the fluxes associated with sand and dust transport. Here we use a wind tunnel and novel sediment trap to capture the fractions of sand in creep, reptation and saltation at Earth and Mars pressures and show that the threshold of motion for aeolian sand transport is best defined as a continuum in which grains progress through stages defined by the proportion of grains in creep and saltation. We propose the use of scale dependent thresholds modeled by distinct probability distribution functions that differentiate the threshold based on micro to macro scale applications. For example, a geologic timescale application corresponds to a threshold when 100% of the bed in motion whereas a sub-second application corresponds to a threshold when a single particle is set in motion. We provide quantitative measurements (number and mode of particle movement) corresponding to visual observations, percent of bed in motion and degrees of transport intermittency for Earth and Mars. Understanding transport as a continuum provides a basis for revaluating sand transport thresholds on Earth, Mars and Titan.

  7. Hydrodynamic calculation of a filter sand bed type used in the containment venting systems

    International Nuclear Information System (INIS)

    Cuevas V, D.; Sainz M, E.; Ortiz V, J.

    2015-09-01

    The filtered venting of the containment has been adopted in European countries to mitigate the consequences of excess pressure containment during a severe accident. When venting has taken place, the fission products are released directly into the environment, unless a filter on the same path is placed, so that various types of filters are used to trap the fission products. The venting filters of the containment currently installed use different filtration technologies that involve more than one medium. Those using water as the first stage of filtration are called wet systems and are equipped with additional steps to remove water drops and fine aerosols emissions. And even they may also be equipped with an element containing certain absorption means for the filtration of gaseous iodine species. Other designs based on filtration of deep bed as the primary retention step; called dry filters, use filtration media of metal fiber, ceramic or sand to trap aerosols. This paper evaluates the hydraulic characteristics of the filter sand bed type designed by EDF as a candidate to be installed in the containment of BWR Mark II (type of primary containment of the nuclear power plant of Laguna Verde). The evaluation of filter sand bed type was performed using the software package of open source OpenFOAM. Models of each zone of the filtered device were generated and through a series of parametric calculations of computational fluid mechanics relevant hydrodynamic characteristics of the device were obtained, such as pressure drops against mass flow rate and pressure fields and speed at different operating conditions. On the other hand, the model validation of the sand bed filter when comparing the results of experimental tests on a sand column of PITEAS program (1985-1986) against OpenFOAM simulation was realized. The results are very close to those obtained experimentally. (Author)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-07-15

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

  9. Co-occurrence of methanogenesis and N{sub 2} fixation in oil sands tailings

    Energy Technology Data Exchange (ETDEWEB)

    Collins, C.E. Victoria [Department of Renewable Resources, University of Alberta, Edmonton, AB T6G 2G7 (Canada); Foght, Julia M. [Department of Biological Sciences, University of Alberta, Edmonton, AB T6G 2E9 (Canada); Siddique, Tariq, E-mail: tariq.siddique@ualberta.ca [Department of Renewable Resources, University of Alberta, Edmonton, AB T6G 2G7 (Canada)

    2016-09-15

    Oil sands tailings ponds in northern Alberta, Canada have been producing biogenic gases via microbial metabolism of hydrocarbons for decades. Persistent methanogenic activity in tailings ponds without any known replenishment of nutrients such as fixed nitrogen (N) persuaded us to investigate whether N{sub 2} fixation or polyacrylamide (PAM; used as a tailings flocculant) could serve as N sources. Cultures comprising mature fine tailings (MFT) plus methanogenic medium supplemented with or deficient in fixed N were incubated under an N{sub 2} headspace. Some cultures were further amended with citrate, which is used in oil sands processing, as a relevant carbon source, and/or with PAM. After an initial delay, N-deficient cultures with or without PAM produced methane (CH{sub 4}) at the same rate as N-containing cultures, indicating a mechanism of overcoming apparent N-deficiency. Acetylene reduction and {sup 15}N{sub 2} incorporation in all N-deficient cultures (with or without PAM) suggested active N{sub 2} fixation concurrently with methanogenesis but inability to use PAM as a N source. 16S rRNA gene pyrosequencing revealed little difference between archaeal populations regardless of N content. However, bacterial sequences in N-deficient cultures showed enrichment of Hyphomicrobiaceae and Clostridium members that might contain N{sub 2}-fixing species. The results are important in understanding long-term production of biogenic greenhouse gases in oil sands tailings. - Highlights: • Methanogenesis in oil sands tailings can occur under nitrogen depleted conditions. • {sup 15}N{sub 2} isotopic analysis reveals that indigenous microbes can fix N{sub 2} for microbial metabolism and methanogenesis. • 16S rRNA gene analysis suggests that members of Hyphomicrobiaceae and Clostridium may be involved in N{sub 2} fixation. • This is the first report that describes co-occurrence of methanogenesis and nitrogen fixation in oil sands tailings.

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

    Science.gov (United States)

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

    2009-01-01

    A unique set of high-quality downhole shallow subsurface well log data combined with industry standard 3D seismic data from the Alaminos Canyon area has enabled the first detailed description of a concentrated gas hydrate accumulation within sand in the Gulf of Mexico. The gas hydrate occurs within very fine grained, immature volcaniclastic sands of the Oligocene Frio sand. Analysis of well data acquired from the Alaminos Canyon Block 818 #1 ("Tigershark") well shows a total gas hydrate occurrence 13??m thick, with inferred gas hydrate saturation as high as 80% of sediment pore space. Average porosity in the reservoir is estimated from log data at approximately 42%. Permeability in the absence of gas hydrates, as revealed from the analysis of core samples retrieved from the well, ranges from 600 to 1500 millidarcies. The 3-D seismic data reveals a strong reflector consistent with significant increase in acoustic velocities that correlates with the top of the gas-hydrate-bearing sand. This reflector extends across an area of approximately 0.8??km2 and delineates the minimal probable extent of the gas hydrate accumulation. The base of the inferred gas-hydrate zone also correlates well with a very strong seismic reflector that indicates transition into units of significantly reduced acoustic velocity. Seismic inversion analyses indicate uniformly high gas-hydrate saturations throughout the region where the Frio sand exists within the gas hydrate stability zone. Numerical modeling of the potential production of natural gas from the interpreted accumulation indicates serious challenges for depressurization-based production in settings with strong potential pressure support from extensive underlying aquifers.

  11. Oil sand synfuel production using nuclear energy

    International Nuclear Information System (INIS)

    Barnert, H.

    1984-10-01

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

  12. Sand control systems used in completing wells

    Directory of Open Access Journals (Sweden)

    Gabriel Wittenberger

    2005-12-01

    Full Text Available Expandable Tubular Technology is transforming the face of well completion and construction. This technology provides: a substantially higher hydrocarbon production rates from the reservoir, a reduced well drilling and construction costs, new possibilities for previously unreachable or uneconomic reservoirs, and step a change towards the single diameter well. ESS (Expandable Sand Screen has an unrivalled performance worldwide for delivering a reliable sand control in a wide range of applications. Well costs typically cut by over 20 %, and the productivity increases up to 70 %.

  13. Relationships of daily mortality and hospital admissions to air pollution in Castilla-Leon, Spain

    Energy Technology Data Exchange (ETDEWEB)

    De Pablo, F.; Lopez, A.; Rivas Soriano, L.; Tomas, C. [Facultad de Ciencias, Universidad de Salamanca (Spain)]. E-mail: fpd123@usal.es; Diego, L.; Gonzalez, M. [Instituto Regional de Salud Publica, SACYL Castilla-Leon (Spain); Barrueco, M. [Facultad de Medicina, Universidad de Salamanca (Spain)

    2006-01-15

    We examined the possible relationships between pollutant concentrations and mortality at seven different locations of Castilla-Leon, Spain, and the relationships between such concentration levels and emergency admissions (morbidity) at four hospitals in the region, taking into account the possible masking effect of other atmospheric variables. The study was based on daily mortality and morbidity data from 1995 to 1997 (ICD-9 codes: 390-459 cardiovascular; 460-519 respiratory; 520-579 digestive causes); moreover, data for meteorological variables (air temperature, relative humidity, solar radiation, atmospheric pressure and wind velocity) and air pollution data (SO{sub 2}, O{sub 3}, NO, NO{sub 2} and CO) were used. A minimum set of weather and pollutant predictors was selected using forward inclusion stepwise linear regression methods and these were used to produce a multivariate model of the different causes of mortality and morbidity. For the whole period, the mortality attributable to cardiovascular causes had an incidence higher than the mortality due to respiratory and digestive causes. The frequency distributions corresponding to the different diseases as classified by ages revealed that the population older than 69 is the most affected, the proportion of cardiovascular disease related deaths in this age sector being 7-fold higher than for the rest of the groups. Mortality and morbidity due to respiratory and cardiovascular-related diseases showed a high correlation coefficient with temperature, solar radiation and ozone, and in general significant correlations were also seen with SO{sub 2}. [Spanish] Se analizan las posibles relaciones existentes entre la mortalidad de la poblacion, el numero de admisiones hospitalarias (morbilidad) y los niveles de concentracion de contaminantes medidos en siete localidades y cuatro hospitales de Castilla-Leon, Espana, respectivamente, teniendo en cuenta el posible efecto de enmascaramiento que ejercen las variables

  14. Successful Control of Ebola Virus Disease: Analysis of Service Based Data from Rural Sierra Leone.

    Directory of Open Access Journals (Sweden)

    Kamalini Lokuge

    2016-03-01

    Full Text Available The scale and geographical distribution of the current outbreak in West Africa raised doubts as to the effectiveness of established methods of control. Ebola Virus Disease (EVD was first detected in Sierra Leone in May 2014 in Kailahun district. Despite high case numbers elsewhere in the country, transmission was eliminated in the district by December 2014. We describe interventions underpinning successful EVD control in Kailahun and implications for EVD control in other areas.Internal service data and published reports from response agencies were analysed to describe the structure and type of response activities, EVD case numbers and epidemic characteristics. This included daily national situation reports and District-level data and reports of the Sierra Leone Ministry of Health and Sanitation, and Médecins Sans Frontières (MSF patient data and internal epidemiological reports. We used EVD case definitions provided by the World Health Organisation over the course of the outbreak. Characteristics assessed included level of response activities and epidemiological features such as reported exposure (funeral-related or not, time interval between onset of illness and admission to the EVD Management Centre (EMC, work-related exposures (health worker or not and mortality. We compared these characteristics between two time periods--June to July (the early period of response, and August to December (when coverage and quality of response had improved. A stochastic model was used to predict case numbers per generation with different numbers of beds and a varying percentage of community cases detected.There were 652 probable/confirmed EVD cases from June-December 2014 in Kailahun. An EMC providing patient care opened in June. By August 2014 an integrated detection, treatment, and prevention strategy was in place across the district catchment zone. From June-July to August-December 2014 surveillance and contact tracing staff increased from 1.0 to 8.8 per

  15. Successful Control of Ebola Virus Disease: Analysis of Service Based Data from Rural Sierra Leone.

    Science.gov (United States)

    Lokuge, Kamalini; Caleo, Grazia; Greig, Jane; Duncombe, Jennifer; McWilliam, Nicholas; Squire, James; Lamin, Manjo; Veltus, Emily; Wolz, Anja; Kobinger, Gary; de la Vega, Marc-Antoine; Gbabai, Osman; Nabieu, Sao; Lamin, Mohammed; Kremer, Ronald; Danis, Kostas; Banks, Emily; Glass, Kathryn

    2016-03-01

    The scale and geographical distribution of the current outbreak in West Africa raised doubts as to the effectiveness of established methods of control. Ebola Virus Disease (EVD) was first detected in Sierra Leone in May 2014 in Kailahun district. Despite high case numbers elsewhere in the country, transmission was eliminated in the district by December 2014. We describe interventions underpinning successful EVD control in Kailahun and implications for EVD control in other areas. Internal service data and published reports from response agencies were analysed to describe the structure and type of response activities, EVD case numbers and epidemic characteristics. This included daily national situation reports and District-level data and reports of the Sierra Leone Ministry of Health and Sanitation, and Médecins Sans Frontières (MSF) patient data and internal epidemiological reports. We used EVD case definitions provided by the World Health Organisation over the course of the outbreak. Characteristics assessed included level of response activities and epidemiological features such as reported exposure (funeral-related or not), time interval between onset of illness and admission to the EVD Management Centre (EMC), work-related exposures (health worker or not) and mortality. We compared these characteristics between two time periods--June to July (the early period of response), and August to December (when coverage and quality of response had improved). A stochastic model was used to predict case numbers per generation with different numbers of beds and a varying percentage of community cases detected. There were 652 probable/confirmed EVD cases from June-December 2014 in Kailahun. An EMC providing patient care opened in June. By August 2014 an integrated detection, treatment, and prevention strategy was in place across the district catchment zone. From June-July to August-December 2014 surveillance and contact tracing staff increased from 1.0 to 8.8 per confirmed

  16. Chromium Contamination in Leon Valley Mexico: Insights from Chromium Stable Isotopes

    Science.gov (United States)

    Villalobos-Aragon, A.; Ellis, A. S.; Armienta, M. A.; Morton, O.; Johnson, T. M.; Glessner, J. J.

    2008-12-01

    Chromium (Cr) is a contaminant commonly found in surface and groundwater. In nature Cr commonly occurs in two valences: Cr(VI) is highly mobile, toxic and carcinogenic, while Cr(III) is less mobile. Cr was first detected in groundwater in the Leon Valley region (located in central Mexico) in 1975 (Rodriguez and Armienta, 1995). Previous work proposed an anthropogenic origin for a high concentration plume near the industrial Buenavista (BV), while the larger sub ppb plume located near San Juan de Otates (SJO) is assumed to be caused by weathering of the SJO pyroxenite. Cr stable isotopes have been shown to be useful in monitoring reduction and can also be used to infer redox and transport conditions in natural settings and the goals of our research are: 1) use stable isotope values (δ53Cr) to monitor Cr behavior in the Leon Valley, 2) identify sources (industrial vs. weathering of ultramafic rocks). Since 1975, the highly contaminated BV area is showing a decrease in groundwater Cr(VI) concentrations. Our sampling in 2007 show Cr(VI) concentrations decreasing from 0.005mg/l to 121mg/l to 0.002mg/l to 95.1mg/l. However, the Cr waste piles still exit and Cr(VI) concentrations from leachate collection ponds range from 1.2g/l to 6.8g/l. Isotopic values obtained from leaching experiments performed on the waste pile samples show enriched δ53Cr values (0.76‰ to 3.25‰) either indicating varying reduction or that the waste is fractionated during the ore processing. δ53Cr values for groundwater range from 0.33‰ to 0.46‰, indicating minimal reduction and lack of available reducing agents. The lack of variation of isotopic values seen in the groundwater plume is also consistent with the results of previous studies showing insignificant fractionation due to sorption within the plume (Villalobos-Aragon et al., 2008). The unfractionated Cr(VI) in groundwater vs. those of the waste piles, considered the contamination source, suggests that either 1) the Cr in the waste

  17. Prediction of sedimentation and consolidation of fine tails

    Energy Technology Data Exchange (ETDEWEB)

    Eckert, W.F.; Masliyah, J.H.; Gray, M.R.; Fedorak, P.M. [Univ. of Alberta, Edmonton, Alberta (Canada). Dept. of Chemical Engineering

    1996-04-01

    Sedimentation and consolidation of suspensions of fine particles were analyzed by integrating experimental measurement of properties in a centrifuge with a comprehensive numerical model. The yield stress and settling velocity for tailings from tar sands extraction were determined experimentally as a function of the volume fraction of solids. The evaluated state functions were used to simulate batch settling and consolidation, and the results compare well with long-term settling tube tests. This approach is very attractive where gravity sedimentation may take many years, and it allows prediction of the rate of clear water production, total time for sedimentation and consolidation, and the maximum concentration of solids. Scaling of the sedimentation between centrifuge and field conditions is discussed. Conversion of permeability-void ratio relationships from geotechnical experiments to state functions of hindered settling velocity is demonstrated, allowing the use of data derived from a variety of experimental techniques.

  18. Investigation of the rebound number and compressive strength of concrete with quarry dust as fine aggregate

    Directory of Open Access Journals (Sweden)

    Sinthaworn Suppachai

    2017-01-01

    Full Text Available This article presents the consideration of relation between compressive strength and rebound number of concrete cooperating with quarry dust as fine aggregate (natural river sand was replaced by quarry dust at the rate of 0%, 25%, 50%, 75% and 100% by weight of fine aggregate. The properties of the tested concrete samples are w/c = 0.6, maximum size of coarse aggregate is 20 mm., cement contents are between 308 and 348 kg/m3, slumps range from 0 to 100 mm., the 28-day compressive strength from 14 to 30 MPa. It was found that the rebound number results were affected by quarry dust especially the standard deviator of rebound number. The cube compressive strength at 28 days and the supplementary curve from the instruction manual were discussed. Moreover, the prediction equation is proposed to estimate the compressive strength of concrete cooperating with quarry dust as fine aggregate.

  19. Properties of Fine Aggregate-Replaced High Volume Class F Fly Ash Concrete

    Directory of Open Access Journals (Sweden)

    Rafat SIDDIQUE

    2013-06-01

    Full Text Available This study focused on evaluating the effects of replacement of fine aggregate (sand with high percentages of Class F fly ash on the properties of concrete. A Control mixture was designed to have 28 days cube compressive strength of 30 MPa, and then fine aggregate was replaced with three percentages (35, 45, and 55% of Class F fly ash by mass. Tests were performed for compressive strength, splitting tensile strength, flexural strength, modulus of elasticity, and abrasion resistance. Test results indicated that replacement of fine aggregate with high volumes of Class F fly ash increased 28 days compressive strength, splitting tensile strength, flexural strength, modulus of elasticity, and abrasion resistance depending upon the fly ash content, and showed continuous improvement at later ages (91 and 365 days.

  20. Fines stabilizing agent reduces production decline rates in steam injected wells

    Energy Technology Data Exchange (ETDEWEB)

    Castillo de Castillo, Milagros; Fernandez Andrades, Jarvi [PDVSA - Petroleos de Venezuela S.A., Caracas (Venezuela); Navarro Cornejo, Willian; Curtis, James [BJ Services do Brasil Ltda., RJ (Brazil)

    2004-07-01

    The Bachaquero Lago heavy oil field, located in Lake Maracaibo, Venezuela, with an area of 9800 ha, in which more than 1800 wells have been drilled. The Lagunillas formation in this field is a mature, clastic, unconsolidated sandstone of Miocene age with good permeability. Clays are present, in laminated form or dispersed within the productive sandstones. Heavy oil, less than 12 deg API, is produced by cyclic steam injection. Wells are completed with cased-hole gravel packs to prevent sand and fines production. Rapid production decline rates are typically observed after the steam injection cycles, due to fines migration and plugging of the reservoir and gravel pack. This paper describes the methodology used to treat the wells with a fines stabilizing agent during the steam injection cycles in order to successfully reduce the subsequent production decline rate. Results from a multi-well pilot project are presented and analyzed. (author)

  1. Impact of civil war on emotion recognition: the denial of sadness in Sierra Leone.

    Directory of Open Access Journals (Sweden)

    Maria Alessandra eUmilta'

    2013-09-01

    Full Text Available Studies of children with atypical emotional experience demonstrate that childhood exposure to high levels of hostility and threat biases emotion perception. This study investigates emotion processing, in former child soldiers and non-combatant civilians. All participants have experienced prolonged violence exposure during childhood. The study, carried out in Sierra Leone, aimed to examine the effects of exposure to and forced participation in acts of extreme violence on the emotion processing of young adults war survivors. A total of 76 young, male adults (38 former child soldier survivors and 38 civilian survivors were tested in order to assess participants’ ability to identify four different facial emotion expressions from photographs and movies. Both groups were able to recognize facial expressions of emotion. However, despite their general ability to correctly identify facial emotions, participants showed a significant response bias in their recognition of sadness. Both former soldiers and civilians made more errors in identifying expressions of sadness than in the other three emotions and when mislabeling sadness participants most often described it as anger. Conversely, when making erroneous identifications of other emotions, participants were most likely to label the expressed emotion as sadness. In addition, while for three of the four emotions participants were better able to make a correct identification the greater the intensity of the expression, this pattern was not observed for sadness. During movies presentation the recognition of sadness was significantly worse for soldiers. While both former child soldiers and civilians were found to be able to identify facial emotions, a significant response bias in their attribution of negative emotions was observed. Such bias was particularly pronounced in former child soldiers. These findings point to a pervasive long-lasting effect of childhood exposure to violence on emotion processing

  2. Potential Impact of Sexual Transmission on Ebola Virus Epidemiology: Sierra Leone as a Case Study.

    Directory of Open Access Journals (Sweden)

    Jessica L Abbate

    2016-05-01

    Full Text Available Sexual transmission of Ebola virus disease (EVD 6 months after onset of symptoms has been recently documented, and Ebola virus RNA has been detected in semen of survivors up to 9 months after onset of symptoms. As countries affected by the 2013-2015 epidemic in West Africa, by far the largest to date, are declared free of Ebola virus disease (EVD, it remains unclear what threat is posed by rare sexual transmission events that could arise from survivors.We devised a compartmental mathematical model that includes sexual transmission from convalescent survivors: a SEICR (susceptible-exposed-infectious-convalescent-recovered transmission model. We fitted the model to weekly incidence of EVD cases from the 2014-2015 epidemic in Sierra Leone. Sensitivity analyses and Monte Carlo simulations showed that a 0.1% per sex act transmission probability and a 3-month convalescent period (the two key unknown parameters of sexual transmission create very few additional cases, but would extend the epidemic by 83 days [95% CI: 68-98 days] (p < 0.0001 on average. Strikingly, a 6-month convalescent period extended the average epidemic by 540 days (95% CI: 508-572 days, doubling the current length, despite an insignificant rise in the number of new cases generated.Our results show that reductions in the per sex act transmission probability via abstinence and condom use should reduce the number of sporadic sexual transmission events, but will not significantly reduce the epidemic size and may only minimally shorten the length of time the public health community must maintain response preparedness. While the number of infectious survivors is expected to greatly decline over the coming months, our results show that transmission events may still be expected for quite some time as each event results in a new potential cluster of non-sexual transmission. Precise measurement of the convalescent period is thus important for planning ongoing surveillance efforts.

  3. Contact tracing performance during the Ebola virus disease outbreak in Kenema district, Sierra Leone.

    Science.gov (United States)

    Senga, Mikiko; Koi, Alpha; Moses, Lina; Wauquier, Nadia; Barboza, Philippe; Fernandez-Garcia, Maria Dolores; Engedashet, Etsub; Kuti-George, Fredson; Mitiku, Aychiluhim Damtew; Vandi, Mohamed; Kargbo, David; Formenty, Pierre; Hugonnet, Stephane; Bertherat, Eric; Lane, Christopher

    2017-05-26

    Contact tracing in an Ebola virus disease (EVD) outbreak is the process of identifying individuals who may have been exposed to infected persons with the virus, followed by monitoring for 21 days (the maximum incubation period) from the date of the most recent exposure. The goal is to achieve early detection and isolation of any new cases in order to prevent further transmission. We performed a retrospective data analysis of 261 probable and confirmed EVD cases in the national EVD database and 2525 contacts in the Contact Line Lists in Kenema district, Sierra Leone between 27 April and 4 September 2014 to assess the performance of contact tracing during the initial stage of the outbreak. The completion rate of the 21-day monitoring period was 89% among the 2525 contacts. However, only 44% of the EVD cases had contacts registered in the Contact Line List and 6% of probable or confirmed cases had previously been identified as contacts. Touching the body fluids of the case and having direct physical contact with the body of the case conferred a 9- and 20-fold increased risk of EVD status, respectively. Our findings indicate that incompleteness of contact tracing led to considerable unmonitored transmission in the early months of the epidemic. To improve the performance of early outbreak contact tracing in resource poor settings, our results suggest the need for prioritized contact tracing after careful risk assessment and better alignment of Contact Line Listing with case ascertainment and investigation.This article is part of the themed issue 'The 2013-2016 West African Ebola epidemic: data, decision-making and disease control'. © 2017 The Author(s).

  4. Effects of Large-Scale Acquisition on Food Insecurity in Sierra Leone

    Directory of Open Access Journals (Sweden)

    Genesis Tambang Yengoh

    2015-07-01

    Full Text Available The recent phenomenon of large-scale acquisition of land for a variety of investment purposes has raised deep concerns over the food security, livelihood and socio-economic development of communities in many regions of the developing world. This study set out to investigate the food security outcomes of land acquisitions in northern Sierra Leone. Using a mixture of quantitative and qualitative research methods, the study measures the severity of food insecurity and hunger, compares the situation of food security before and after the onset of operations of a land investing company, analyzes the food security implications of producing own food versus depending on wage labour for household food needs, and evaluates initiatives put in place by the land investing company to mitigate its food insecurity footprint. Results show an increase in the severity of food insecurity and hunger. Household income from agricultural production has fallen. Employment by the land investing company is limited in terms of the number of people it employs relative to the population of communities in which it operates. Also, wages from employment by the company cannot meet the staple food needs of its employees. The programme that has been put in place by the company to mitigate its food insecurity footprint is failing because of a host of reasons that relate to organization and power relations. In conclusion, rural people are better off producing their own food than depending on the corporate structure of land investment companies. Governments should provide an enabling framework to accommodate this food security need, both in land investment operations that are ongoing and in those that are yet to operate.

  5. Reductions in inpatient mortality following interventions to improve emergency hospital care in Freetown, Sierra Leone.

    Directory of Open Access Journals (Sweden)

    Matthew Clark

    Full Text Available BACKGROUND: The demand for high quality hospital care for children in low resource countries is not being met. This paper describes a number of strategies to improve emergency care at a children's hospital and evaluates the impact of these on inpatient mortality. In addition, the cost-effectiveness of improving emergency care is estimated. METHODS AND FINDINGS: A team of local and international staff developed a plan to improve emergency care for children arriving at The Ola During Children's Hospital, Freetown, Sierra Leone. Following focus group discussions, five priority areas were identified to improve emergency care; staff training, hospital layout, staff allocation, medical equipment, and medical record keeping. A team of international volunteers worked with local staff for six months to design and implement improvements in these five priority areas. The improvements were evaluated collectively rather than individually. Before the intervention, the inpatient mortality rate was 12.4%. After the intervention this improved to 5.9%. The relative risk of dying was 47% (95% CI 0.369-0.607 lower after the intervention. The estimated number of lives saved in the first two months after the intervention was 103. The total cost of the intervention was USD 29 714, the estimated cost per death averted was USD 148. There are two main limitation of the study. Firstly, the brevity of the study and secondly, the assumed homogeneity of the clinical cases that presented to the hospital before and after the intervention. CONCLUSIONS: This study demonstarted a signficant reductuion in inpatient mortality rate after an intervention to improve emergency hospital care If the findings of this paper could be reproduced in a larger more rigorous study, improving the quality of care in hospitals would be a very cost effective strategy to save children's lives in low resource settings.

  6. Diversity of inland valleys and opportunities for agricultural development in Sierra Leone.

    Directory of Open Access Journals (Sweden)

    Elliott Ronald Dossou-Yovo

    Full Text Available Inland valleys are becoming increasingly important agricultural production areas for rural households in sub-Saharan Africa due to their relative high and secure water availability and soil fertility. In addition, inland valleys are important as water buffer and biodiversity hot spots and they provide local communities with forest, forage, and fishing resources. As different inland-valley ecosystem functions may conflict with agricultural objectives, indiscriminate development should be avoided. This study aims to analyze the diversity of inland valleys in Sierra Leone and to develop guidelines for more precise interventions. Land use, biophysical and socio-economic data were analyzed on 257 inland valleys using spatial and multivariate techniques. Five cluster groups of inland valleys were identified: (i semi-permanently flooded with high soil organic carbon (4.2% and moderate available phosphorus (10.2 ppm, mostly under natural vegetation; (ii semi-permanently flooded with low soil organic carbon (1.5% and very low available phosphorus (3.1 ppm, abandoned by farmers; (iii seasonally flooded with moderate soil organic carbon (3.1% and low available phosphorus (8.3 ppm, used for rainfed rice and off-season vegetables produced without fertilizer application for household consumption and market; (iv well drained with moderate soil organic carbon (3.8% and moderate available phosphorus (10.0 ppm, used for rainfed rice and off-season vegetables produced with fertilizer application for household consumption and market; and (v well drained with moderate soil organic carbon (3.6% and moderate available phosphorus (11 ppm, used for household consumption without fertilizer application. Soil organic carbon, available phosphorus, hydrological regime, physical accessibility and market opportunity were the major factors affecting agricultural intensification of inland valleys. Opening up the areas in which inland valleys occur through improved roads and

  7. The Potential of Women’s Organization for Rural Development in Sierra Leone

    Directory of Open Access Journals (Sweden)

    Theresa Tenneh Dick

    2013-01-01

    Full Text Available Organizations are among the preferred outlets women use both to voice societal prejudices against them and to showcase their potential for rural/community development. There is an increasing advocacy for gender equality, women’s empowerment and the integration of women folks into the socio-economic, political and cultural fabrics of society. Girl-child education and women-based capacity building programs such as micro-finance, entrepreneurship, political activism, etc. have surfaced prominently on these women’s empowerment efforts. In this study, a questionnaire-driven survey is conducted in two districts in southern Sierra Leone. The survey covers 36 influential women in 36 town-level communities in the country. The study analyzes the personal and organization characteristics of the women in relation to social perceptions and rural/community development. A large percent of the women surveyed are educated, married and belong to social organizations. In addition to other social/development organizations, women’s organizations are also present in each of the surveyed communities. Most of the women organizations are local in nature and operate entirely on funds raised from within the local communities. This display of organizational ability of the surveyed rural women shows a significant perceptional shift towards recognizing women folks as productive counterparts in our societies. This trend also psychologically strengthens the women community to take on tangible responsibilities that were ones meant for men only. The analysis also shows that rural women hold managerial and other administrative positions in the organizations which are strongly oriented towards various forms of rural/community development. This is a significant positive deviation from the traditional perception which has unduly confined the women folks to the backyard for centuries now. This trend not only has the potential of benefiting the millions more women languishing in

  8. New Experiences in Dike Construction with Soil-Ash Composites and Fine-Grained Dredged Materials

    Science.gov (United States)

    Duszyński, Remigiusz; Duszyńska, Angelika; Cantré, Stefan

    2017-12-01

    The supporting structure inside a coastal dike is often made of dredged non-uniform sand with good compaction properties. Due to the shortage of natural construction material for both coastal and river dikes and the surplus of different processed materials, new experiments were made with sand-ash mixtures and fine-grained dredged materials to replace both dike core and dike cover materials resulting in economical, environmentally friendly and sustainable dikes. Ash from EC Gdańsk and dredged sand from the Vistula river were mixed to form an engineering material used for dike construction. The optimum sand-ash composites were applied at a field test site to build a large-scale research dike. Fine-grained dredged materials from Germany were chosen to be applied in a second full-scale research dike in Rostock. All materials were investigated according to the standards for soil mechanical analysis. This includes basic soil properties, mechanical characteristics, such as grain-size distribution, compaction parameters, compressibility, shear strength, and water permeability. In the field, the infiltration of water into the dike body as well as the erosion resistance of the cover material against overflowing water was determined. Results of both laboratory and field testing are discussed in this paper. In conclusion, the mixing of bottom ash with mineral soil, such as relatively uniform dredged sand, fairly improves the geotechnical parameters of the composite, compared to the constituents. Depending on the composite, the materials may be suitable to build a dike core or an erosion-resistant dike cover.

  9. New Experiences in Dike Construction with Soil-Ash Composites and Fine-Grained Dredged Materials

    Directory of Open Access Journals (Sweden)

    Duszyński Remigiusz

    2017-12-01

    Full Text Available The supporting structure inside a coastal dike is often made of dredged non-uniform sand with good compaction properties. Due to the shortage of natural construction material for both coastal and river dikes and the surplus of different processed materials, new experiments were made with sand-ash mixtures and fine-grained dredged materials to replace both dike core and dike cover materials resulting in economical, environmentally friendly and sustainable dikes. Ash from EC Gdańsk and dredged sand from the Vistula river were mixed to form an engineering material used for dike construction. The optimum sand-ash composites were applied at a field test site to build a large-scale research dike. Fine-grained dredged materials from Germany were chosen to be applied in a second full-scale research dike in Rostock. All materials were investigated according to the standards for soil mechanical analysis. This includes basic soil properties, mechanical characteristics, such as grain-size distribution, compaction parameters, compressibility, shear strength, and water permeability. In the field, the infiltration of water into the dike body as well as the erosion resistance of the cover material against overflowing water was determined. Results of both laboratory and field testing are discussed in this paper. In conclusion, the mixing of bottom ash with mineral soil, such as relatively uniform dredged sand, fairly improves the geotechnical parameters of the composite, compared to the constituents. Depending on the composite, the materials may be suitable to build a dike core or an erosion-resistant dike cover.

  10. Carbon stock estimates for forests in the Castilla y Leon region, Spain. A GIS based method for evaluating spatial distribution of residual biomass for bio-energy

    Energy Technology Data Exchange (ETDEWEB)

    Gil, Maria Victoria; Blanco, Daniel; Carballo, Maria Teresa; Calvo, Luis Fernando [Chemical Engineering, Institute of Natural Resources, University of Leon, Avenida de Portugal, 41, 24071 Leon (Spain)

    2011-01-15

    Analysis of aboveground biomass and carbon stocks (as equivalent CO{sub 2}) was performed in the Castilla y Leon region, Spain. Data from the second and third Spanish Forest Inventories (1996 and 2006) were used. Total aboveground biomass was calculated using allometric biomass equations and biomass expansion factors (BEF), the first method giving higher values. Forests of Castilla y Leon stored 77,051,308 Mg of biomass, with a mean of 8.18 Mg ha{sup -1}, in 1996 and 135,531,737 Mg of biomass, with a mean of 14.4 Mg ha{sup -1}, in 2006. The total equivalent CO{sub 2} in this region's forests increased 9,608,824 Mg year{sup -1} between 1996 and 2006. In relation to the Kyoto Protocol, the Castilla y Leon forests have sequestered 3 million tons of CO{sub 2} per year, which represents 6.4% of the total regional emission of CO{sub 2}. A Geographic Information System (GIS) based method was also used to assess the geographic distribution of residual forest biomass for bio-energy in the region. The forest statistics data on area of each species were used. The fraction of vegetation cover, land slope and protected areas were also considered. The residual forest biomass in Castilla y Leon was 1,464,991 Mg year{sup -1}, or 1.90% of the total aboveground biomass in 1996. The residual forest biomass was concentrated in specific zones of the Castilla y Leon region, suitable for the location of industries that utilize biomass as energy source. The energy potential of the residual forest biomass in the Castilla y Leon region is 7350 million MJ per year. (author)

  11. [Western area surge for controlling Ebola hemorrhagic fever outbreak in Sierra Leone and evaluation of its effect].

    Science.gov (United States)

    Chen, Yong; Wu, Dan; Zhang, Wenyi; Chen, Zeliang; Chang, Guohui; Tian, Shuguang; Yang, Ruifu; Liu, Chao

    2015-10-01

    To investigate the Western Area Surge (WAS) program in the Ebola outbreak of Sierra Leone, and to analyze its implementing effect. The subject of this study was 3,813 laboratory confirmed Ebola hemorrhagic fever (EHF) cases reported in Sierra Leone from November 19, 2014 through January 27, 2015, a period before and after the implementation of the WAS program. To analyze and make conclusions according to the working experience of China Mobile Laboratory Reponses Team in the fight of Ebola outbreak, using WHO published EHF case definition to make diagnosis and compare the number of bed numbers, confirmed EHF cases, samples tested, and positive rates before and after implementation of WAS program. From the implementation of WAS program on 17th December 2014 to half a month later, the total numbers of Ebola holding and treatment centers increased from 640 to 960, six additional laboratories were established. On January, 2015, another two laboratories from America and The Netherlands were established. The numbers of samples tested one month before and after WAS program were 7,891 and 9,783, respectively, with an increase of 24.0 percent, while the positive rate of Ebola virus decreased from 22.2% (1,752/7,891) to 11.0% (1,077/9,783). The positive rate of blood samples decreased from 39.6% (248/626) in the month before WAS program to 27.4% (131/478) (χ2=17.93, P<0.001) in the mother after WAS program, the positive rate of blood samples 22.7% (103/454) to 10% (62/609) (χ2=31.03, P<0.001), accordingly. After 3 weeks of WAS program, in addition to Western Area, another four hotspots in Sierra Leone had also reported a significant decrease of the numbers of confirmed EVD cases. Forty-two days after implementation of WAS program, the daily number of laboratory confirmed EHF cases decreased from 63 to 10. WAS program played a vital role in controlling the EHF outbreak rapidly in Sierra Leone. It could also provide guidance for the control similar large infectious diseases

  12. Evaluating the use of cell phone messaging for community Ebola syndromic surveillance in high risked settings in Southern Sierra Leone.

    Science.gov (United States)

    Jia, Kangbai; Mohamed, Koroma

    2015-09-01

    Most underdeveloped countries do not meet core disease outbreak surveillance because of the lack of human resources, laboratory and infrastructural facilities. The use of cell phone technology for disease outbreak syndromic surveillance is a new phenomenon in Sierra Leone despite its successes in other developing countries like Sri Lanka. In this study we set to evaluate the effectiveness of using cell phone technology for Ebola hemorrhagic fever syndromic surveillance in a high risked community in Sierra Leone. This study evaluated the effectiveness of using cell phone messaging (text and calls) for community Ebola hemorrhagic fever syndromic surveillance in high risked community in southern Sierra Leone. All cell phone syndromic surveillance data used for this study was reported as cell phone alert messages-texts and voice calls; by the Moyamba District Health Management Team for both Ebola hemorrhagic fever suspect and mortalities. We conducted a longitudinal data analysis of the monthly cumulative confirmed Ebola hemorrhagic fever cases and mortalities collected by both the traditional sentinel and community cell phone syndromic surveillance from August 2014 to October 2014. A total of 129 and 49 Ebola hemorrhagic fever suspect and confirmed cases respectively were recorded using the community Ebola syndromic surveillance cell phone alert system by the Moyamba District Health Management Team in October 2014. The average number of Ebola hemorrhagic fever suspects and confirmed cases for October 2014 were 4.16 (Std.dev 3.76) and 1.58 (Std.dev 1.43) respectively. Thirty-four percent (n=76) of the community Ebola syndromic surveillance cell phone alerts that were followed-up within 24 hours reported Ebola hemorrhagic fever suspect cases while 65.92% (n=147) reported mortality. Our study suggests some form of underreporting by the traditional sentinel Ebola hemorrhagic fever disease surveillance system in Moyamba District southern Sierra Leone for August

  13. Heavy mineral potential of Athabasca oil sands

    Energy Technology Data Exchange (ETDEWEB)

    Coward, J.; Oxenford, J. [Syncrude Canada Ltd., Edmonton, AB (Canada)

    1997-11-01

    There are three large scale production operations in the Athabasca oil sands: (1) Syncrude, a surface mining plant that has been operating since 1978 at a current synthetic oil production rate of over 205,000 barrels per day, (2) the Suncor operation, also a surface mining plant, in operation since 1967 and producing about 80,000 barrels per day of synthetic oil and (3) Esso`s Cold Lake operation, an in-situ operation that extracts the oil from the deposits in the ground and produces about 95,000 barrels per day of bitumen. The presence of heavy metals in the Athabasca oil sands was discussed, emphasizing current trends in the heavy mineral industry and various conditions and options for the development of this resource. The typical heavy minerals include magnetite, ilmenite, leucoxene, rutile, zircon, monazite, sillimanite, kyanite, and garnet. Several potentially attractive investment options exist to develop this byproduct of oil sands mining. The potential impact on the heavy mineral industry that may result from the development of heavy minerals from oil sands was also explored. 23 refs., 10 tabs., 5 figs.

  14. Growing markets to sustain oil sands development

    International Nuclear Information System (INIS)

    Wise, T.H.

    2003-01-01

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

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

    Science.gov (United States)

    Pas, An; Dubey, J P

    2008-09-01

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

  16. Our Footprints on the Sands of Time

    Indian Academy of Sciences (India)

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

  17. Geomechanical properties of lime stabilized clayey sands

    International Nuclear Information System (INIS)

    Arabani, M.; Karami, M. Veis

    2007-01-01

    Clayey sands that have low plasticity, low compressibility and high strength under loads, are suitable as a base material for any engineering construction projects as well as for roads and building construction. Decrease of plasticity and compressibility as well as increase in strength of these materials can be obtained by many different methods. Of these methods, lime stabilization is a common, applicable, and easy to use approach that can improve geomechanical and geotechnical properties of clayey sand fills. In this study some important geomechanical properties and geotechnical properties of clayey sands including compressive strength, CBR and elastic plastic behavior are investigated. A range of gradations representative of those gradations found in situ in the north of Iran were selected for testing and samples were artificially rebuilt in the laboratory. The mixes were then stabilized with hydrated lime and cured. Different mechanical tests were performed on mature materials. The stress-strain behavior of lime-stabilized mixes was plotted and a parabolic function was used to estimate the trend of stress-strain behavior. The data show that there is a correlation among the results of uniaxial load test, tensile strength, and CBR of the tested specimens. Also, results of the unconfined compression test and the indirect tensile strength test show that an increase in clay content up to a certain percent, in the clay-sand fills, tends to increase the strength of the materials in compression as well as in tension. (author)

  18. Afyon-Sandıklı

    Indian Academy of Sciences (India)

    Sandıklı-Hüdai geothermal field is one of the geothermal systems in Afyon and environ, located approx- imately 40 km southwest of Afyon. The study area consists of volcanic, sedimentary and metamorphic rocks. Kestel greenschist formation of Paleozoic age forms the basement rock in the area while quartzite which is a ...

  19. The impact of raindrops on sand

    NARCIS (Netherlands)

    de Jong, Rianne

    2017-01-01

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

  20. experimental investigation of sand minimum transport velocity

    African Journals Online (AJOL)

    user

    The justification for experimental work was evident from the inconsistent and inaccurate results obtained using existing analytical models for MTV predictions. .... At the end of each experimental run, the sand particle was separated from mixture using a filter. The water is then re-circulated into the system continuously.

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

    African Journals Online (AJOL)

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

  2. V-2 Rocket at White Sands

    Science.gov (United States)

    1946-01-01

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

  3. Sand transport, erosion and granular electrification

    DEFF Research Database (Denmark)

    Merrison, J.P.

    2012-01-01

    The transport of granular materials by wind has a major impact on our environment through sand/soil erosion and the generation and transport of atmospheric dust aerosols. Terrestrially the transport of dust involves billions of tons of material every year, influencing the global climate and impac......The transport of granular materials by wind has a major impact on our environment through sand/soil erosion and the generation and transport of atmospheric dust aerosols. Terrestrially the transport of dust involves billions of tons of material every year, influencing the global climate...... can affect grain transport through the generation of intense electric fields and processes of electrostatic assembly. Importantly the transport of sand is characterized by saltation, which is known to be an active process for erosion and therefore a source for dust and sand formation. Using novel...... erosion simulation techniques the link between grain transport rates and erosion rates has been quantified. Furthermore this can be linked to production rates for dust and has been associated with chemical and mineral alteration through a process of mechanical activation of fractured surfaces. This work...

  4. Radiation safety in Australia's mineral sands industry

    International Nuclear Information System (INIS)

    Hughes, W.

    1989-06-01

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

  5. Operating sand and environment: can harmonising?

    Directory of Open Access Journals (Sweden)

    Eriton Geraldo Vieira

    2015-12-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-12-31

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

  7. Dark grains of sand: a geological storytelling

    Science.gov (United States)

    Gallo Maresca, Magda

    2017-04-01

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

  8. Lessons learned from comparisons of mesotidal sand- and mudflats

    Science.gov (United States)

    Nittrouer, Charles A.; Raubenheimer, Britt; Wheatcroft, Robert A.

    2013-06-01

    Tidal flats with limited vegetation provide valuable opportunities to investigate the linkages of hydrodynamics and sediment dynamics. A mudflat in southern Willapa Bay and a sandflat in Skagit Bay (both Washington state, USA) are characterized by processes with many similarities, but some differences. In particular, one imports mud and the other exports mud. Classic intertidal mechanisms (e.g., flood/ebb asymmetry, settling/scour lags) cause net landward transport onto the southern Willapa tidal flat, and the details of the interlinked processes are complex. Meandering channels with dendritic planform are the circulatory system for this site, and are entrenched in cohesive clayey silt. Tidal range and wind/wave conditions are similar in the two areas, but the direct discharges of fluvial freshwater and sediment are much greater for Skagit Bay. When coupled with the other processes operating there, mud export from the Skagit tidal flat is the net result. Braided channels dominate the Skagit site, and migrate freely through non-cohesive fine sand. An integrated summary is presented here for a multi-investigator study of these two areas, and the detailed results are described by the papers that follow.

  9. 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....

  10. Testing and evaluation of recovered traction sanding material.

    Science.gov (United States)

    2013-04-01

    The Montana Department of Transportation (MDT) is searching for a solution to the accumulation of traction sand that is applied to Montana highways every winter. An analysis of reuse and recycle options for salvaged traction sand was conducted using ...

  11. 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.

  12. Quality stabilisation of synthetic sand containing bentonite in process lines

    OpenAIRE

    A. Fedoryszyn

    2010-01-01

    Stabilisation of sand quality requires the monitoring and control of sand moisture contents and its other parameters at each stage of sandprocessing, i.e. during the preparation of return sand mix and rebonding processes. Stabilisation of sand quality necessitates the use of reliable control equipment and evaluation procedures. This study outlines the scope and results of research work aimed to improve the control equipment to enhance the performance of turbine mixers. The paper reviews the m...

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

    Directory of Open Access Journals (Sweden)

    Daneshi Navab

    2014-06-01

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

  14. HIV/AIDS practice patterns, knowledge, and educational needs among Hispanic clinicians in Texas, USA, and Nuevo Leon, Mexico

    Directory of Open Access Journals (Sweden)

    Martinez J. Louis

    1998-01-01

    Full Text Available Hispanic clinicians in Texas, United States of America, and in the neighboring state of Nuevo Leon, Mexico, were surveyed to determine their educational needs in the area of HIV/AIDS. Two-thirds of the 74 Texan and 22% of the 104 Mexican physicians queried had seen at least one HIV/AIDS patient in the previous year. The majority of the respondents were primary care physicians who: 1 were in private practice; 2 saw more than 1 000 patients per year; 3 had been out of training for more than 10 years; 4 provided some HIV prevention education to patients based on their perceived risk of infection; 5 rated their own knowledge of HIV/AIDS as average but rated their knowledge of treatments for the disease below average; 6 received most of their information about HIV/AIDS from journals rather than formal continuing education programs; 7 thought Hispanic patients had special needs with regard to HIV/AIDS care; and 8 were willing to attend education programs to improve their HIV/AIDS management skills. The greatest barriers to caring for HIV patients were lack of clinical knowledge and fear of infection. These results point to a need for a large-scale training program to improve the HIV/AIDS management skills of Hispanic clinicians in Texas and Nuevo Leon.

  15. Iodine Status of Women of Reproductive Age in Sierra Leone and Its Association with Household Coverage with Adequately Iodized Salt

    Directory of Open Access Journals (Sweden)

    Fabian Rohner

    2016-02-01

    Full Text Available Salt iodization programs are a public health success in tackling iodine deficiency. Yet, a large proportion of the world’s population remains at risk for iodine deficiency. In a nationally representative cross-sectional survey in Sierra Leone, household salt samples and women’s urine samples were quantitatively analyzed for iodine content. Salt was collected from 1123 households, and urine samples from 817 non-pregnant and 154 pregnant women. Household coverage with adequately iodized salt (≥15 mg/kg iodine was 80.7%. The median urinary iodine concentration (UIC of pregnant women was 175.8 µg/L and of non-pregnant women 190.8 µg/L. Women living in households with adequately iodized salt had higher median UIC (for pregnant women: 180.6 µg/L vs. 100.8 µg/L, respectively, p < 0.05; and for non-pregnant women: 211.3 µg/L vs. 97.8 µg/L, p < 0.001. Differences in UIC by residence, region, household wealth, and women’s education were much smaller in women living in households with adequately iodized salt than in households without. Despite the high household coverage of iodized salt in Sierra Leone, it is important to reach the 20% of households not consuming adequately iodized salt. Salt iodization has the potential for increasing equity in iodine status even with the persistence of other risk factors for deficiency.

  16. High coverage of vitamin A supplementation and measles vaccination during an integrated Maternal and Child Health Week in Sierra Leone.

    Science.gov (United States)

    Sesay, Fatmata F; Hodges, Mary H; Kamara, Habib I; Turay, Mohamed; Wolfe, Adam; Samba, Thomas T; Koroma, Aminata S; Kamara, Wogba; Fall, Amadou; Mitula, Pamela; Conteh, Ishata; Maksha, Nuhu; Jambai, Amara

    2015-01-01

    In May 2012, the twice-yearly Maternal and Child Health Week (MCHW) integrated vitamin A supplementation (VAS) and supplementary measles vaccination to reach all children 6-59 months in Sierra Leone. Following the MCHW, a post event coverage survey was conducted to validate VAS coverage and assess adverse events following immunization. Using the WHO Expanded Program on Immunization sampling methodology, 30 clusters were randomly selected using population proportionate to size sampling. Fourteen caregivers of children 6-59 months were interviewed per cluster for precision of ±5%. Responses were collected via mobile phones using EpiSurveyor. Overall VAS and measles coverage was 91.9% and 91.6%, respectively, with no significant differences by age group, sex, religion or occupation. Major reasons given for not receiving VAS and measles vaccination were not knowing about the MCHW or being out of the area. Significantly more mild adverse events (fever, pain at injection site) were reported via the post event coverage survey (29.1%) than MCHW (0.01%) (p90% of children in Sierra Leone with equitable coverage. Increased reporting of mild adverse events during the survey may be attributed to delayed onset after measles vaccination and/or direct inquiry from enumerators. Even mild adverse events following immunization requires strengthened reporting during and after vaccination campaigns. © The Author 2014. Published by Oxford University Press on behalf of Royal Society of Tropical Medicine and Hygiene. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  17. Female Genital Mutilation in Sierra Leone: Forms, Reliability of Reported Status, and Accuracy of Related Demographic and Health Survey Questions

    Science.gov (United States)

    Grant, Donald S.; Berggren, Vanja

    2013-01-01

    Objective. To determine forms of female genital mutilation (FGM), assess consistency between self-reported and observed FGM status, and assess the accuracy of Demographic and Health Surveys (DHS) FGM questions in Sierra Leone. Methods. This cross-sectional study, conducted between October 2010 and April 2012, enrolled 558 females aged 12–47 from eleven antenatal clinics in northeast Sierra Leone. Data on demography, FGM status, and self-reported anatomical descriptions were collected. Genital inspection confirmed the occurrence and extent of cutting. Results. All participants reported FGM status; 4 refused genital inspection. Using the WHO classification of FGM, 31.7% had type Ib; 64.1% type IIb; and 4.2% type IIc. There was a high level of agreement between reported and observed FGM prevalence (81.2% and 81.4%, resp.). There was no correlation between DHS FGM responses and anatomic extent of cutting, as 2.7% reported pricking; 87.1% flesh removal; and 1.1% that genitalia was sewn closed. Conclusion. Types I and II are the main forms of FGM, with labia majora alterations in almost 5% of cases. Self-reports on FGM status could serve as a proxy measurement for FGM prevalence but not for FGM type. The DHS FGM questions are inaccurate for determining cutting extent. PMID:24204384

  18. Female Genital Mutilation in Sierra Leone: Forms, Reliability of Reported Status, and Accuracy of Related Demographic and Health Survey Questions

    Directory of Open Access Journals (Sweden)

    Owolabi Bjälkander

    2013-01-01

    Full Text Available Objective. To determine forms of female genital mutilation (FGM, assess consistency between self-reported and observed FGM status, and assess the accuracy of Demographic and Health Surveys (DHS FGM questions in Sierra Leone. Methods. This cross-sectional study, conducted between October 2010 and April 2012, enrolled 558 females aged 12–47 from eleven antenatal clinics in northeast Sierra Leone. Data on demography, FGM status, and self-reported anatomical descriptions were collected. Genital inspection confirmed the occurrence and extent of cutting. Results. All participants reported FGM status; 4 refused genital inspection. Using the WHO classification of FGM, 31.7% had type Ib; 64.1% type IIb; and 4.2% type IIc. There was a high level of agreement between reported and observed FGM prevalence (81.2% and 81.4%, resp.. There was no correlation between DHS FGM responses and anatomic extent of cutting, as 2.7% reported pricking; 87.1% flesh removal; and 1.1% that genitalia was sewn closed. Conclusion. Types I and II are the main forms of FGM, with labia majora alterations in almost 5% of cases. Self-reports on FGM status could serve as a proxy measurement for FGM prevalence but not for FGM type. The DHS FGM questions are inaccurate for determining cutting extent.

  19. Surveillance of Vector-Borne Infections (Chikungunya, Dengue, and Malaria) in Bo, Sierra Leone, 2012-2013.

    Science.gov (United States)

    Dariano, Donald F; Taitt, Chris R; Jacobsen, Kathryn H; Bangura, Umaru; Bockarie, Alfred S; Bockarie, Moses J; Lahai, Joseph; Lamin, Joseph M; Leski, Tomasz A; Yasuda, Chadwick; Stenger, David A; Ansumana, Rashid

    2017-10-01

    Malaria remains a significant cause of morbidity and mortality in West Africa, but the contribution of other vector-borne infections (VBIs) to the burden of disease has been understudied. We used rapid diagnostic tests (RDTs) for three VBIs to test blood samples from 1,795 febrile residents of Bo City, Sierra Leone, over a 1-year period in 2012-2013. In total, 24% of the tests were positive for malaria, fewer than 5% were positive for markers of dengue virus infection, and 39% were positive for IgM directed against chikungunya virus (CHIKV) or a related alphavirus. In total, more than half (55%) of these febrile individuals tested positive for at least one of the three VBIs, which highlights the very high burden of vector-borne diseases in this population. The prevalence of positives on the Chikungunya IgM and dengue tests did not vary significantly with age ( P > 0.36), but higher rates of malaria were observed in children Chikungunya IgM RDTs were moderately correlated with rainfall ( r 2 = 0.599). Based on the high prevalence of positive results on the Chikungunya IgM RDTs from individuals Bo and its environs, there is a need to examine whether an ecological shift toward a greater burden from CHIKV or related alphaviruses is occurring in other parts of Sierra Leone or the West African region.

  20. Knowledge Attitude And Practice Of Street Food Vendors In Selected Schools Within Bo City Southern Sierra Leone

    Directory of Open Access Journals (Sweden)

    P.T. Lamin-Boima

    2017-12-01

    Full Text Available This paper attempts to investigate the lack of knowledge attitude and practices of street food vendors in Bo the Southern Province of Sierra Leone. A cross sectional study conducted among eighty-seven respondents vendors in forty-four in Bo City. Data was collected using a structured and semi structured questionnaire. The collected data is analysed using a simple descriptive statistics with the help Excel Microsoft ware. A statistical significance was found in relation to knowledge. Attitude towards food safety was negative self-reported practices by Street Food Vendors were statistically significant with low hygiene standards while predisposing factors showed relatively low personal hygiene poor environmental sanitation and low food safety practice. The realize consequences are utmost health risks of consuming street foods as food contamination has caused food borne diseases and outbreaks. It is recommended that standard training be provided for these vendors by the Bo City Council in collaboration with Njala University. It is essential that poor people in a developing country such as Sierra Leone be allowed to earn their livelihood by means of an easy-to-enter business such as street food vending when hygiene standards are sustained.