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Sample records for northern congo fan

  1. Gas hydrate decomposition recorded by authigenic barite at pockmark sites of the northern Congo Fan

    Science.gov (United States)

    Kasten, Sabine; Nöthen, Kerstin; Hensen, Christian; Spieß, Volkhard; Blumenberg, Martin; Schneider, Ralph R.

    2012-12-01

    The geochemical cycling of barium was investigated in sediments of pockmarks of the northern Congo Fan, characterized by surface and subsurface gas hydrates, chemosynthetic fauna, and authigenic carbonates. Two gravity cores retrieved from the so-called Hydrate Hole and Worm Hole pockmarks were examined using high-resolution pore-water and solid-phase analyses. The results indicate that, although gas hydrates in the study area are stable with respect to pressure and temperature, they are and have been subject to dissolution due to methane-undersaturated pore waters. The process significantly driving dissolution is the anaerobic oxidation of methane (AOM) above the shallowest hydrate-bearing sediment layer. It is suggested that episodic seep events temporarily increase the upward flux of methane, and induce hydrate formation close to the sediment surface. AOM establishes at a sediment depth where the upward flux of methane from the uppermost hydrate layer counterbalances the downward flux of seawater sulfate. After seepage ceases, AOM continues to consume methane at the sulfate/methane transition (SMT) above the hydrates, thereby driving the progressive dissolution of the hydrates "from above". As a result the SMT migrates downward, leaving behind enrichments of authigenic barite and carbonates that typically precipitate at this biogeochemical reaction front. Calculation of the time needed to produce the observed solid-phase barium enrichments above the present-day depths of the SMT served to track the net downward migration of the SMT and to estimate the total time of hydrate dissolution in the recovered sediments. Methane fluxes were higher, and the SMT was located closer to the sediment surface in the past at both sites. Active seepage and hydrate formation are inferred to have occurred only a few thousands of years ago at the Hydrate Hole site. By contrast, AOM-driven hydrate dissolution as a consequence of an overall net decrease in upward methane flux seems to

  2. From Black Hole to Hydrate Hole: Gas hydrates, authigenic carbonates and vent biota as indicators of fluid migration at pockmark sites of the Northern Congo Fan

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    Kasten, S.; Schneider, R.; Spiess, V.; Cruise Participants Of M56b

    2003-04-01

    A recent high-resolution seismic, echosounder and video survey combined with detailed geological and geochemical sampling of pockmark sites on the Northern Congo Fan was carried out with RV Meteor in November/December 2002 in the frame of the project "CONGO" (BMBF/BEO "Geotechnologien"). These investigations revealed the extensive occurrence of surface and sub-surface gas hydrates as well as characteristic features of fluid venting such as clams (Calyptogena), tube worms (Pogonophera) and huge amounts of authigenic carbonates. In a first approach the patchyness in the occurrence of these features was mapped in relation to pockmark structure and seismic reflectors. Detailed sampling of three pockmarks by gravity corer showed that gas hydrates are present at and close to the sediment surface and often occur as several distinct layers and/or veins intercalated with hemipelagic muds. The depth of the upper boundary of these hydrate-bearing sediments increases from the center towards the edge of the pockmark structures. Pore water concentration profiles of sulfate and methane document the process of anaerobic methane oxidation above the hydrate-bearing layers. For those cores which contained several gas hydrate layers preliminary pore water profiles suggest the occurrence of more than one zone of anaerobic methane oxidation. Authigenic carbonates are found in high abundance, irregularly distributed within the pockmarks close to the sediment surface. These carbonates occur in a wide variety with respect to size, shape, structure and mineralogy. Their formation is associated with high amounts of bicarbonate released by the process of anaerobic methane oxidation. In the gravity cores authigenic carbonates are always present above hydrate-bearing sections. However, the quantities and characteristics of these authigenic minerals in relation to venting and microbial activity as well as to gas hydrate dissociation are not clear yet. Unraveling this relationship will be a major

  3. Early to middle Miocene foraminifera from the deep-sea Congo Fan, offshore Angola

    OpenAIRE

    Kender, S; Kaminski, M.A.; Jones, R W

    2008-01-01

    Analysis of a 630m section of an exploration well penetrating the distal part of the Congo Fan (~2000m water depth) yielded high abundance and diversity assemblages of agglutinated and calcareous benthic foraminifera. Planktonic foraminifera constrain the age to Early – Middle Miocene, and \\delta 18O records reveal the Mi1 (~16.3 Ma) isotopic shift. Relatively few taxonomic studies of deep-water calcareous and agglutinated benthic foraminifera exist from this time period in this loca...

  4. Aliphatic hydrocarbons and triterpenes of the Congo deep-sea fan

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    Méjanelle, Laurence; Rivière, Béatrice; Pinturier, Laurence; Khripounoff, Alexis; Baudin, François; Dachs, Jordi

    2017-08-01

    Hydrocarbons were analyzed in sediments from the Congo River deep-sea fan, from the Congo River, and in sinking particles collected by sediment traps 40 m above the sediment. Studied sites encompassed three lobes of decreasing age of formation along the canyon: sites A, F and C and a another lobe system, disconnected from the active channel since 4 ka, Site E. Terrestrial long-chain odd n-alkanes were dominant in all sediments of the lobe system. Unsaturated terpenoids sourced by higher plants, such as gammacerene, lupene, ursene and oleanene, were also detected. At site C, characterized by high accumulation rates (10-20 cm yr-1), the organic matter spends less time in the oxic layer than at other sites and high phytadiene concentrations 10-17 μg gOC-1) evidenced recent terrestrial and phytoplanktonic remains reworked in anaerobic conditions. In these sediments, organic carbon-normalized concentrations of terrestrial alkanes and terpenoids were several fold higher than in the lobe sediments with lower accumulation rates (sites A and F), arguing for a more rapid degradation of terrestrial hydrocarbons than bulk organic carbon in the first steps of pre-diagenesis. Ample variations in the contributions of biomarkers from higher plants, ferns, bacteria and angiosperms, indicate an heterogeneous contribution of the soil and vegetation detritus delivered to the Congo lobe sediments. Lower concentrations in terrestrial hydrocarbons at site E, 45 km away from the active canyon, indicated that river particles are still admixed to the dominant marine organic matter. Diploptene and hop-7(21)-ene have a dual origin, from terrestrial and marine microorganisms. Scatter in their relationship to gammacerene argues for a contribution of marine microorganisms, in addition to soils-sourced microorganisms. The close distribution patterns of diploptene, hop-21-ene, hop-7(21)ene and neohop-13(18)-ene is in line with the hypothesis of sequential clay-catalyzed isomerisation of bacterial

  5. Pore-fluid chemistry along the main axis of an active lobe at the Congo deep-sea fan

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    Croguennec, C.; Ruffine, L.; Guyader, V.; Le Bruchec, J.; Ruesch, B.; Caprais, J.; Cathalot, C.; de Prunelé, A.; Germain, Y.; Bollinger, C.; Dennielou, B.; Olu, K.; Rabouille, C.

    2013-12-01

    The distal lobes of the Congo deep-sea fan constitute a unique in situ laboratory to study early diagenesis of marine sediments. They are located at water depth of about 5000 m and result from the deposition of sediment transported by turbidity currents along the channel-levee systems and submarine canyon connected to the Congo River. Thus, a huge amount of organic matter, transported from the river to the lobes, undergoes decomposition processes involving different oxidants present within the sedimentary column. This drastically changes the chemistry of the pore fluids, allowing the occurence of a succession of biogeochemical processes. The present study is part of an ongoing project which aims at better understanding the role and the fate of organic matter transported to the lobe systems, as well as its implication in the distribution of the living communities encountered there. Thus, pore fluids have been sampled from 8 Calypso cores in order to determine the concentration of dissolved elements. Five sites have been investigated: four of them are located along the main axis of a currently active lobe, the last one being located on a lobe disconnected from the chenals. The analyses of methane, major (Cl, SO4, Mg, Ca, K, Na) and minor (Sr, Ba, B, Li, Mn) elements have been carried out along with total alkalinity determination. The resulting profiles show a highly heterogeneous pore-fluid chemistry. Sulphate concentration near the seawater/sediment interface varies from 3 to 29 mM, indicating intense sulphate reduction. Surprisingly the lowest values are found at the site which is disconnected from the active lobe. The manganese cycle is well defined for all cores. The core recovered at the more distal lobe exhibits very peculiar pore-fluid profiles which are likely related to a geological event, most likely sediment slide and remobilization. References: Babonneau, N., Savoye, B., Cremer, M. & Klein, B., 2002. Morphology and architecture of the present canyon and

  6. Palynofacies reveal fresh terrestrial organic matter inputs in the terminal lobes of the Congo deep-sea fan

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    Schnyder, Johann; Stetten, Elsa; Baudin, François; Pruski, Audrey M.; Martinez, Philippe

    2017-08-01

    The Congo deep-sea fan is directly connected to the Congo River by a unique submarine canyon. The Congo River delivers up to 2×1012gPOC/yr, a part of which is funnelled by the submarine canyon and feeds the deep-sea environments. The more distal part of the Congo deep-sea fan, the terminal lobe area, has a surface of 2500 km2 and is situated up to 800 km offshore at depths of 4750-5000 m. It is a remarkable place to study the fate and distribution of the organic matter transferred from the continent to the deep ocean via turbidity currents. Forty-two samples were analyzed from the terminal lobes, including sites from the active channel, one of its levees and an abandoned distal channel. Samples were collected using multitube cores and push-cores using a Victor 6000 ROV, which surveyed the dense chemosynthetic habitats that locally characterize the terminal lobes. Palynofacies reveal a remarkably well-preserved, dominantly terrestrial particulate organic matter assemblage, that has been transferred from the continent into the deep-sea by turbidity currents. Delicate plant structures, cuticle fragments and plant cellular material is often preserved, highlighting the efficiency of turbidity currents to transfer terrestrial organic matter to the sea-floor, where it is preserved. Moreover, the palynofacies data reveal a general sorting by density or buoyancy of the organic particles, as the turbulent currents escaped the active channel, feeding the levees and the more distal, abandoned channel area. Finally, in addition to aforementioned hydrodynamic factors controlling the organic matter accumulation, a secondary influence of chemosynthetic habitats on organic matter preservation is also apparent. Palynofacies is therefore a useful tool to record the distribution of organic matter in recent and ancient deep-sea fan environments, an important topic for both academic and petroleum studies.

  7. Mineralization of vestimentiferan tubes at methane seeps on the Congo deep-sea fan

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    Haas, Antonie; Little, Crispin T. S.; Sahling, Heiko; Bohrmann, Gerhard; Himmler, Tobias; Peckmann, Jörn

    2009-02-01

    Vestimentiferan tube worms are prominent members of modern methane seep communities and are totally reliant as adults on symbiotic sulphide-oxidizing bacteria for their nutrition. The sulphide is produced in the sediment by a biochemical reaction called the anaerobic oxidation of methane (AOM). A well-studied species from the Gulf of Mexico shows that seep vestimentiferans 'mine' sulphide from the sediment using root-like, thin walled, permeable posterior tube extensions, which can also be used to pump sulphate and possibly hydrogen ions from the soft tissue back into the sediment to increase the local rate of AOM. The 'root-balls' of exhumed seep vestimentiferans are intimately associated with carbonate nodules, which are a result of AOM. We have studied vestimentiferan specimens and associated carbonates from seeps at the Kouilou pockmark field on the Congo deep-sea fan and find that some of the posterior 'root' tubes of living specimens are enclosed with carbonate indurated sediment and other, empty examples are partially or completely replaced by the carbonate mineral aragonite. This replacement occurs from the outside of the tube wall inwards and leaves fine-scale relict textures of the original organic tube wall. The process of mineralization is unknown, but is likely a result of post-mortem microbial decay of the tube wall proteins by microorganisms or the precipitation from locally high flux of AOM derived carbonate ions. The aragonite-replaced tubes from the Kouilou pockmarks show similar features to carbonate tubes in ancient seep deposits and make it more likely that many of these fossil tubes are those of vestimentiferans. These observations have implications for the supposed origination of this group, based on molecular divergence estimates.

  8. Relative Abundance and Diversity of Bacterial Methanotrophs at the Oxic–Anoxic Interface of the Congo Deep-Sea Fan

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    Laurent Toffin

    2017-04-01

    Full Text Available Sitting at ∼5,000 m water depth on the Congo-Angola margin and ∼760 km offshore of the West African coast, the recent lobe complex of the Congo deep-sea fan receives large amounts of fluvial sediments (3–5% organic carbon. This organic-rich sedimentation area harbors habitats with chemosynthetic communities similar to those of cold seeps. In this study, we investigated relative abundance, diversity and distribution of aerobic methane-oxidizing bacteria (MOB communities at the oxic–anoxic interface of sedimentary habitats by using fluorescence in situ hybridization and comparative sequence analysis of particulate mono-oxygenase (pmoA genes. Our findings revealed that sedimentary habitats of the recent lobe complex hosted type I and type II MOB cells and comparisons of pmoA community compositions showed variations among the different organic-rich habitats. Furthermore, the pmoA lineages were taxonomically more diverse compared to methane seep environments and were related to those found at cold seeps. Surprisingly, MOB phylogenetic lineages typical of terrestrial environments were observed at such water depth. In contrast, MOB cells or pmoA sequences were not detected at the previous lobe complex that is disconnected from the Congo River inputs.

  9. Relative Abundance and Diversity of Bacterial Methanotrophs at the Oxic-Anoxic Interface of the Congo Deep-Sea Fan.

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    Bessette, Sandrine; Moalic, Yann; Gautey, Sébastien; Lesongeur, Françoise; Godfroy, Anne; Toffin, Laurent

    2017-01-01

    Sitting at ∼5,000 m water depth on the Congo-Angola margin and ∼760 km offshore of the West African coast, the recent lobe complex of the Congo deep-sea fan receives large amounts of fluvial sediments (3-5% organic carbon). This organic-rich sedimentation area harbors habitats with chemosynthetic communities similar to those of cold seeps. In this study, we investigated relative abundance, diversity and distribution of aerobic methane-oxidizing bacteria (MOB) communities at the oxic-anoxic interface of sedimentary habitats by using fluorescence in situ hybridization and comparative sequence analysis of particulate mono-oxygenase (pmoA) genes. Our findings revealed that sedimentary habitats of the recent lobe complex hosted type I and type II MOB cells and comparisons of pmoA community compositions showed variations among the different organic-rich habitats. Furthermore, the pmoA lineages were taxonomically more diverse compared to methane seep environments and were related to those found at cold seeps. Surprisingly, MOB phylogenetic lineages typical of terrestrial environments were observed at such water depth. In contrast, MOB cells or pmoA sequences were not detected at the previous lobe complex that is disconnected from the Congo River inputs.

  10. Energy transfer in the Congo deep-sea fan: From terrestrially-derived organic matter to chemosynthetic food webs

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    Pruski, A. M.; Decker, C.; Stetten, E.; Vétion, G.; Martinez, P.; Charlier, K.; Senyarich, C.; Olu, K.

    2017-08-01

    Large amounts of recent terrestrial organic matter (OM) from the African continent are delivered to the abyssal plain by turbidity currents and accumulate in the Congo deep-sea fan. In the recent lobe complex, large clusters of vesicomyid bivalves are found all along the active channel in areas of reduced sediment. These soft-sediment communities resemble those fuelled by chemoautotrophy in cold-seep settings. The aim of this study was to elucidate feeding strategies in these macrofaunal assemblages as part of a greater effort to understand the link between the inputs of terrestrially-derived OM and the chemosynthetic habitats. The biochemical composition of the sedimentary OM was first analysed in order to evaluate how nutritious the available particulate OM is for the benthic macrofauna. The terrestrial OM is already degraded when it reaches the final depositional area. However, high biopolymeric carbon contents (proteins, carbohydrates and lipids) are found in the channel of the recent lobe complex. In addition, about one to two thirds of the nitrogen can be assigned to peptide-like material. Even if this soil-derived OM is poorly digestible, turbiditic deposits contain such high amounts of organic carbon that there is enough biopolymeric carbon and proteacinous nitrogen to support dense benthic communities that contrast with the usual depauperate abyssal plains. Stable carbon and nitrogen isotopes and fatty acid biomarkers were then used to shed light on the feeding strategies allowing the energy transfer from the terrestrial OM brought by the turbidity currents to the abyssal food web. In the non-reduced sediment, surface detritivorous holothurians and suspension-feeding poriferans rely on detritic OM, thereby depending directly on the turbiditic deposits. The sulphur-oxidising symbiont bearing vesicomyids closely depend on the reprocessing of OM with methane and sulphide as final products. Their carbon and nitrogen isotopic signatures vary greatly among sites

  11. Cold-seep-like macrofaunal communities in organic- and sulfide-rich sediments of the Congo deep-sea fan

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    Olu, K.; Decker, C.; Pastor, L.; Caprais, J.-C.; Khripounoff, A.; Morineaux, M.; Ain Baziz, M.; Menot, L.; Rabouille, C.

    2017-08-01

    Methane-rich fluids arising from organic matter diagenesis in deep sediment layers sustain chemosynthesis-based ecosystems along continental margins. This type of cold seep develops on pockmarks along the Congo margin, where fluids migrate from deep-buried paleo-channels of the Congo River, acting as reservoirs. Similar ecosystems based on shallow methane production occur in the terminal lobes of the present-day Congo deep-sea fan, which is supplied by huge quantities of primarily terrestrial material carried by turbiditic currents along the 800 km channel, and deposited at depths of up to nearly 5000 m. In this paper, we explore the effect of this carbon enrichment of deep-sea sediments on benthic macrofauna, along the prograding lobes fed by the current active channel, and on older lobes receiving less turbiditic inputs. Macrofaunal communities were sampled using either USNEL cores on the channel levees, or ROV blade cores in the chemosynthesis-based habitats patchily distributed in the active lobe complex. The exceptionally high organic content of the surface sediment in the active lobe complex was correlated with unusual densities of macrofauna for this depth, enhanced by a factor 7-8, compared with those of the older, abandoned lobe, whose sediment carbon content is still higher than in Angola Basin at same depth. Macrofaunal communities, dominated by cossurid polychaetes and tanaids were also more closely related to those colonizing low-flow cold seeps than those of typical deep-sea sediment. In reduced sediments, microbial mats and vesicomyid bivalve beds displayed macrofaunal community patterns that were similar to their cold-seep counterparts, with high densities, low diversity and dominance of sulfide-tolerant polychaetes and gastropods in the most sulfidic habitats. In addition, diversity was higher in vesicomyid bivalve beds, which appeared to bio-irrigate the upper sediment layers. High beta-diversity is underscored by the variability of geochemical

  12. Origin and distribution of the organic matter in the distal lobe of the Congo deep-sea fan - A Rock-Eval survey

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    Baudin, François; Stetten, Elsa; Schnyder, Johann; Charlier, Karine; Martinez, Philippe; Dennielou, Bernard; Droz, Laurence

    2017-08-01

    The Congo River, the second largest river in the world, is a major source of organic matter for the deep Atlantic Ocean because of the connection of its estuary to the deep offshore area by a submarine canyon which feeds a vast deep-sea fan. The lobe zone of this deep-sea fan is the final receptacle of the sedimentary inputs presently channelled by the canyon and covers an area of 2500 km². The quantity and the source of organic matter preserved in recent turbiditic sediments from the distal lobe of the Congo deep-sea fan were assessed using Rock-Eval pyrolysis analyses. Six sites, located at approximately 5000 m water-depth, were investigated. The mud-rich sediments of the distal lobe contain high amounts of organic matter ( 3.5 to 4% Corg), the origin of which is a mixture of terrestrial higher-plant debris, soil organic matter and deeply oxidized phytoplanktonic material. Although the respective contribution of terrestrial and marine sources of organic matter cannot be precisely quantified using Rock-Eval analyses, the terrestrial fraction is dominant according to similar hydrogen and oxygen indices of both suspended and bedload sediments from the Congo River and that deposited in the lobe complex. The Rock-Eval signature supports the 70% to 80% of the terrestrial fraction previously estimated using C/N and δ13Corg data. In the background sediment, the organic matter distribution is homogeneous at different scales, from a single turbiditic event to the entire lobe, and changes in accumulation rates only have a limited effect on the quantity and quality of the preserved organic matter. Peculiar areas with chemosynthetic bivalves and/or bacterial mats, explored using ROV Victor 6000, show a Rock-Eval signature similar to background sediment. This high organic carbon content associated to high sedimentation rates (> 2 to 20 mm.yr-1) in the Congo distal lobe complex implies a high burial rate for organic carbon. Consequently, the Congo deep-sea fan represents an

  13. Fauna and habitat types driven by turbidity currents in the lobe complex of the Congo deep-sea fan

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    Sen, Arunima; Dennielou, Bernard; Tourolle, Julie; Arnaubec, Aurélien; Rabouille, Christophe; Olu, Karine

    2017-08-01

    This study characterizes the habitats and megafaunal community of the Congo distal lobe complex driven by turbidity currents through the use of remotely operated vehicle (ROV) still imagery transects covering distances in the order of kilometers. In this sedimentary, abyssal area about 5000 m deep and 750 km offshore from western Africa, large quantities of deposited organic material supplied by the Congo River canyon and channel support aggregations of large sized foraminifers (Bathysiphon sp.) and vesicomyid clams (Christineconcha regab, Abyssogena southwardae) often associated with methane cold seeps, as well as opportunistic deep-sea scavengers. Additionally, bacterial mats, assumed to be formed by large sulfur-oxidizing filamentous bacteria (Beggiatoa type), and black patches of presumably reduced sediment were seen which are, together with sulfur-oxidizing symbiont- bearing vesicomyids, indicators of sulfide-rich sediments. Habitat and faunal distribution were analyzed in relation to the microtopography obtained with the ROV multibeam echosounder, at three sites from the entrance of the lobe complex where the channel is still deep, to the main, flatter area of turbidite deposition. Specific characteristics of the system influence animal distributions: both the forams and the vesicomyid clams tended to avoid the channels characterized by high-speed currents, and are therefore preferentially located along channel flanks affected by sliding, and on levees formed by channel overspill. Foram fields are found in flat areas and form large fields, whereas the vesicomyids have a patchy distribution and appear to show a preference for regions of local topographical relief such as slide scars or collapsed blocks of sediments, which likely facilitate sulfide exhumation. The colonization of sulfide rich sediments by vesicomyids is limited, but nonetheless was seen to occur in the main deposition area where they have to cope with very high sedimentation rates (up to 20 cm

  14. Organic carbon transfer and ecosystem functioning in the terminal lobes of the Congo deep-sea fan: outcomes of the Congolobe project

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    Rabouille, C.; Baudin, F.; Dennielou, B.; Olu, K.

    2017-08-01

    The terminal lobe complex of the Congo deep-sea fan is a fascinating environment. It is located at 5000 meters depth and 750 km offshore Africa. It is currently connected with the Congo River by a canyon and deep-sea channel system starting in the estuary and still fed by turbidity currents (Babonneau et al., 2002; Savoye et al., 2000, 2009). It thus displays most of the characteristics of a subaquatic delta: large sedimentation rates, high concentration of organic carbon of terrestrial origin, active diagenesis. In addition, this peculiar zone of the deep ocean hosts unexpected biological assemblages resembling those of cold seeps: chemosynthetic vesicomyid bivalves, microbial mats and reduced sediments in metric size discrete habitats.

  15. Timing and nature of alluvial fan development along the Chajnantor Plateau, northern Chile

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    Cesta, Jason M.; Ward, Dylan J.

    2016-11-01

    Alluvial systems in the Atacama Desert provide a unique opportunity to elucidate the sedimentary response to climate variability, particularly changes in precipitation, in hyperarid environments. Alluvial fans along the eastern margin of the Salar de Atacama, adjacent to the Chajnantor Plateau in the Atacama Desert of northern Chile, provide an archive of climate-modulated sediment transfer and erosion at an extreme of Earth's climate. Three regional alluvial fan surfaces (Qf1 [oldest] to Qf3 [youngest]) were mapped along the western flank of the Chajnantor Plateau. The alluvial fans were examined with geomorphic and terrestrial cosmogenic 36Cl surface exposure dating methods to define the timing of alluvial fan formation and to determine the role of climatic processes on fan development in a hyperarid environment. Alluvial fans in the study area are comprised of hyperconcentrated flow and boulder-rich debris flow deposits that reflect deposition transitioning between cohesive and noncohesive regimes. Alluvial fan surfaces yield exposure ages that range from 49.6 ± 4.4 to 194 ± 12 ka, while debris flow boulders yield exposure ages ranging from 12.4 ± 2.1 to 229 ± 53 ka. Cosmogenic 36Cl exposure ages indicate that abandonment of alluvial fan surfaces Qf1, Qf2, and Qf3 date to 175 ± 22.6 ka (MIS 6), 134.5 ± 9.18 ka (MIS 6), and 20.07 ± 6.26 ka (MIS 2), respectively. A 36Cl concentration-depth profile through alluvial fan Qf1 suggests a simple depositional history with minimal nuclide inheritance implying relatively rapid aggradation (6 m in ca. 25 kyr) followed by surface abandonment ca. 180-200 ka. Our data support a strong climatic control on alluvial fan evolution in the region, and we propose that the alluvial fans along the margins of the Salar de Atacama form according to the humid model of fan formation.

  16. Surface processes on a mud-dominated Mars analogue alluvial fan, Atacama Desert, northern Chile

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    Hobley, D. E.; Howard, A. D.; Morgan, A. M.; Matsubara, Y.; Moore, J. M.; Parsons, R.; Williams, R. M.; Burr, D. M.; Hayes, A. G.; Dietrich, W.

    2012-12-01

    We characterize surface processes on highly unusual terrestrial alluvial fans, which we interpret as a strong analogue for large fans on Mars. The Mars fans date to post-Noachian periods when the martian climate was dominated by cold, hyperarid conditions. Some of the martian fans are differentially eroded to leave their distributary channels in positive relief. This inversion, along with the lack of boulders visible on most fan surfaces, reveals that the dominant grain size of the fans is fine enough for the overbank deposits to be stripped by wind. Degradation, image resolution, and lack of ground truthing all act to obscure the nature of the past flow processes. The fans in the Pampa de Tamarugal of the Atacama Desert of northern Chile are excellent potential Mars analogues for a number of reasons: 1. Hyperaridity, with ~2 mm/y rainfall over the fans themselves, resulting in 2. very little vegetation, 3. no fluvial erosion on the fans themselves, and 4. wind-driven erosion of the fan surfaces; 5. equivalent fan scale (tens of km); 6. similar fan gradient (low); 7. low channel branching density; 8. runoff fed from adjacent, much steeper terrain receiving more precipitation (~500 km2 drainages receiving 0.1-1 m/y precipitation in the High Andes, crater walls and interpreted orographic effects on Mars). Both the modern channels and the preserved stratigraphy are dominated by debris flow-like sheetflow mud deposits. Channels are leveed by concrete-like mass-supported deposits of granules and sand suspended in a silt and clay matrix, often overtopping the channel margins and forming up to 150 m wide levees and km-length sheet flows. This leveeing strongly constrains the aggrading channel, which is typically dominated by better sorted and imbricated fluvial deposits. We infer that the wetter tail of mudlfows sorts the deposits, keeping the central channel unblocked by mud. Relatively few channels are active at any time, but aggradation triggers occasional avulsions

  17. The Congolobe project, a multidisciplinary study of Congo deep-sea fan lobe complex: Overview of methods, strategies, observations and sampling

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    Rabouille, C.; Olu, K.; Baudin, F.; Khripounoff, A.; Dennielou, B.; Arnaud-Haond, S.; Babonneau, N.; Bayle, C.; Beckler, J.; Bessette, S.; Bombled, B.; Bourgeois, S.; Brandily, C.; Caprais, J. C.; Cathalot, C.; Charlier, K.; Corvaisier, R.; Croguennec, C.; Cruaud, P.; Decker, C.; Droz, L.; Gayet, N.; Godfroy, A.; Hourdez, S.; Le Bruchec, J.; Saout, J.; Le Saout, M.; Lesongeur, F.; Martinez, P.; Mejanelle, L.; Michalopoulos, P.; Mouchel, O.; Noel, P.; Pastor, L.; Picot, M.; Pignet, P.; Pozzato, L.; Pruski, A. M.; Rabiller, M.; Raimonet, M.; Ragueneau, O.; Reyss, J. L.; Rodier, P.; Ruesch, B.; Ruffine, L.; Savignac, F.; Senyarich, C.; Schnyder, J.; Sen, A.; Stetten, E.; Sun, Ming Yi; Taillefert, M.; Teixeira, S.; Tisnerat-Laborde, N.; Toffin, L.; Tourolle, J.; Toussaint, F.; Vétion, G.; Jouanneau, J. M.; Bez, M.; Congolobe group:

    2017-08-01

    The presently active region of the Congo deep-sea fan (around 330,000 km2), called the terminal lobes or lobe complex, covers an area of 2500 km2 at 4700-5100 m water depth and 750-800 km offshore. It is a unique sedimentary area in the world ocean fed by a submarine canyon and a channel-levee system which presently deliver large amounts of organic carbon originating from the Congo River by turbidity currents. This particularity is due to the deep incision of the shelf by the Congo canyon, up to 30 km into the estuary, which funnels the Congo River sediments into the deep-sea. The connection between the river and the canyon is unique for major world rivers. In 2011, two cruises (WACS leg 2 and Congolobe) were conducted to simultaneously investigate the geology, organic and inorganic geochemistry, and micro- and macro-biology of the terminal lobes of the Congo deep-sea fan. Using this multidisciplinary approach, the morpho-sedimentary features of the lobes were characterized along with the origin and reactivity of organic matter, the recycling and burial of biogenic compounds, the diversity and function of bacterial and archaeal communities within the sediment, and the biodiversity and functioning of the faunal assemblages on the seafloor. Six different sites were selected for this study: Four distributed along the active channel from the lobe complex entrance to the outer rim of the sediment deposition zone, and two positioned cross-axis and at increasing distance from the active channel, thus providing a gradient in turbidite particle delivery and sediment age. This paper aims to provide the general context of this multidisciplinary study. It describes the general features of the site and the overall sampling strategy and provides the initial habitat observations to guide the other in-depth investigations presented in this special issue. Detailed bathymetry of each sampling site using 0.1-1 m resolution multibeam obtained with a remotely operated vehicle (ROV

  18. Attitudes Towards Forest Elephant Conservation Around a Protected Area in Northern Congo

    Directory of Open Access Journals (Sweden)

    Félicien Nsonsi

    2017-01-01

    Full Text Available An assessment of local attitudes towards conservation can guide wildlife managers in the effective application of measurements to improve these perceptions. Here we conducted a quantitative questionnaire survey around a protected area in northern Congo surveying 314 households living in four villages around the Nouabalé-Ndoki National Park. We investigated the impact of the benefits of a conservation project (led by an international non-governmental organisation, the experience with human-elephant conflict and the respondents' socio-economic profile on local people's attitudes towards forest elephant conservation. Using multivariate analysis, we found overall positive attitudes towards elephant conservation with more positive answers in the village where a conservation project is based. Furthermore, people employed in the conservation project stated more positive attitudes compared to logging company employees famers, natural resource users and people conducting other jobs. Experience of human elephant conflict negatively impacted people's perceptions. Socio-economic variables, such as ethnic group, education level or salary category had relatively little impact on people's responses. Qualitative statements largely supported the questionnaire results. We discuss our results in the light of the limits of attitude surveys and suggest further investigations to identify the activities needed to foster positive attitudes for elephant conservation in all villages around the Nouabalé-Ndoki National Park in partnership with the logging company.

  19. Bushmeat supply and consumption in a tropical logging concession in northern Congo.

    Science.gov (United States)

    Poulsen, J R; Clark, C J; Mavah, G; Elkan, P W

    2009-12-01

    Unsustainable hunting of wildlife for food empties tropical forests of many species critical to forest maintenance and livelihoods of forest people. Extractive industries, including logging, can accelerate exploitation of wildlife by opening forests to hunters and creating markets for bushmeat. We monitored human demographics, bushmeat supply in markets, and household bushmeat consumption in five logging towns in the northern Republic of Congo. Over 6 years we recorded 29,570 animals in town markets and collected 48,920 household meal records. Development of industrial logging operations led to a 69% increase in the population of logging towns and a 64% increase in bushmeat supply. The immigration of workers, jobseekers, and their families altered hunting patterns and was associated with increased use of wire snares and increased diversity in the species hunted and consumed. Immigrants hunted 72% of all bushmeat, which suggests the short-term benefits of hunting accrue disproportionately to "outsiders" to the detriment of indigenous peoples who have prior, legitimate claims to wildlife resources. Our results suggest that the greatest threat of logging to biodiversity may be the permanent urbanization of frontier forests. Although enforcement of hunting laws and promotion of alternative sources of protein may help curb the pressure on wildlife, the best strategy for biodiversity conservation may be to keep saw mills and the towns that develop around them out of forests.

  20. An antigenic investigation of Crimean-Congo hemorrhagic fever virus (CCHFV) in hard ticks from provinces in northern Turkey.

    Science.gov (United States)

    Albayrak, Harun; Ozan, Emre; Kurt, Mitat

    2010-10-01

    Crimean-Congo hemorrhagic fever virus threatens human health. Exposure of the infected tick is a strong risk factor for human disease. In this study, the hard ticks collected from a variety of mammalian species (cattle, sheep, goat, and buffalo) and a turtle in either coastal or inland Black Sea region of Turkey were surveyed for the presence of antigen from Crimean-Congo hemorrhagic fever virus (CCHFV). CCHFV antigen was found in 46 of 421 tick pools (10.92%). Positivity rates for the provinces varied and were as follows: Samsun 33.87%, Ordu 4.34%, Giresun 8.86%, Sinop 6.09%, Amasya 7.40%, Tokat 5.08%, and Sivas 8.06%. CCHFV antigen was detected in seven of 11 tick species tested. These results suggest that these hard ticks may act as a reservoir for CCHFV in northern Turkey.

  1. When Organic-Rich Turbidites Reach 5000 m: "Cold-Seep Like" Life in the Congo Deep-Sea Fan

    Science.gov (United States)

    Pastor, L.; Toffin, L.; Cathalot, C.; Olu, K.; Brandily, C.; Bessette, S.; Lesongeur, F.; Godfroy, A.; Khripounoff, A.; Decker, C.; Taillefert, M.; Rabouille, C.

    2016-12-01

    The Congo canyon, located on the west coast of Africa, is a unique example of a canyon directly connected to a major river (The Congo River). Turbidites are responsible for a large input of terrestrial organic matter at depths up to 5000 m. These high inputs led to global high organic matter mineralization rates, with very localized hot spots that were visually observed and specifically sampled with a ROV. These hot spots, featuring substantial concentration of reduced compounds, mainly methane and sulfides, were recognizable in surface by the presence of reduced sediment patches, bacterial mats, and/or vesicomyid bivalves that host bacterial endosymbionts able to process H2S. In this paper we present geochemical sediment profiles of sulfate, methane, sulfide and dissolved iron together with phylogenetic diversity of 16S rRNA communities. This will give a first understanding of biogeochemical processes occurring in this peculiar ecosystem, mainly sulfate reduction, methanogenesis and subsequent anaerobic oxidation of methane with bacterial and archaeal assemblages similar to cold seeps environments. Iron also seems to play a major role in this system and iron/sulfur interactions as a sink for H2S can probably compete with H2S consumption by chemosynthetic bivalves, estimated at one site by vesicomyds gills incubations in a sulfide-rich solution.

  2. Seabed morphology and sedimentary processes on high-gradient trough mouth fans offshore Troms, northern Norway

    Science.gov (United States)

    Rydningen, Tom Arne; Laberg, Jan Sverre; Kolstad, Vidar

    2015-10-01

    Trough mouth fans (TMF) situated at the mouths of formerly glaciated cross-shelf troughs are important paleoclimatic archives. Whereas the sedimentary processes of large, low-gradient TMFs have received considerable interest, little attention has been paid to the other end member of this landform class, i.e. TMFs with higher slope gradients. Detailed swath-bathymetric data and seismic profiles from the continental margin offshore Troms, northern Norway cover three high-gradient TMFs (the Andfjorden, Malangsdjupet and Rebbenesdjupet TMFs; slope gradients generally between 1° and 15°), as well as inter-fan areas, which include two submarine canyons (the Andøya and Senja Canyon) and the Malangsgrunnen inter-fan slope. The present-day morphologies of the Andfjorden and Malangsdjupet TMFs have evolved from sediment transport and distribution through gully-channel complexes. The Andfjorden TMF has later been affected by a large submarine landslide that remobilized much of these complexes. The Rebbenesdjupet TMF is dominated by a number of small and relatively shallow slide scars, which are inferred to be related to small-scale sediment failure of glaciomarine and/or contouritic sediments. The canyons cut into the adjacent TMFs, and turbidity currents originating on the fans widened and deepened the canyons during downslope flow. The Malangsgrunnen shelf break and inter-fan slope acted as a funnel for turbidity currents originating on the upper slope, forming a dendritic pattern of gullies. A conceptual model for the high-gradient TMFs on the Troms margin has been compiled. The main sediment input onto the TMFs has occurred during peak glacials when the Fennoscandian Ice Sheet reached the shelf edge. The overall convex fan form and progradational seismic facies show that these glacigenic deposits were repeatedly distributed onto the fan. On the Andfjorden and Malangsdjupet TMFs, gully-channel complexes occur within such deposits. It is thus inferred that the steep

  3. Early diagenesis in the sediments of the Congo deep-sea fan dominated by massive terrigenous deposits: Part III - Sulfate- and methane- based microbial processes

    Science.gov (United States)

    Pastor, L.; Toffin, L.; Decker, C.; Olu, K.; Cathalot, C.; Lesongeur, F.; Caprais, J.-C.; Bessette, S.; Brandily, C.; Taillefert, M.; Rabouille, C.

    2017-08-01

    Geochemical profiles (SO42-, H2S, CH4, δ13CH4) and phylogenetic diversity of Archaea and Bacteria from two oceanographic cruises dedicated to the lobes sediments of the Congo deep-sea fan are presented in this paper. In this area, organic-rich turbidites reach 5000 m and allow the establishment of patchy cold-seep-like habitats including microbial mats, reduced sediments, and vesicomyid bivalves assemblages. These bivalves live in endosymbiosis with sulfur-oxidizing bacteria and use sulfides to perform chemosynthesis. In these habitats, unlike classical abyssal sediments, anoxic processes are dominant. Total oxygen uptake fluxes and methane fluxes measured with benthic chambers are in the same range as those of active cold-seep environments, and oxygen is mainly used for reoxidation of reduced compounds, especially in bacterial mats and reduced sediments. High concentrations of methane and sulfate co-exist in the upper 20 cm of sediments, and evidence indicates that sulfate-reducing microorganisms and methanogens co-occur in the shallow layers of these sediments. Simultaneously, anaerobic oxidation of methane (AOM) with sulfate as the electron acceptor is evidenced by the presence of ANMEs (ANaerobic MEthanotroph). Dissolved sulfide produced through the reduction of sulfate is reoxidized through several pathways depending on the habitat. These pathways include vesicomyid bivalves uptake (adults or juveniles in the bacterial mats habitats), reoxidation by oxygen or iron phases within the reduced sediment, or reoxidation by microbial mats. Sulfide uptake rates by vesicomyids measured in sulfide-rich sea water (90±18 mmol S m-2 d-1) were similar to sulfide production rates obtained by modelling the sulfate profile with different bioirrigation constants, highlighting the major control of vesicomyids on sulfur cycle in their habitats.

  4. The Alcyonacea (soft corals and sea fans of Antsiranana Bay, northern Madagascar

    Directory of Open Access Journals (Sweden)

    Alison J. Evans

    2011-06-01

    Full Text Available During the past two decades, the Alcyonacea (soft corals and sea fans of the western Indian Ocean have been the subject of numerous studies investigating their ecology and distribution. Comparatively, Madagascar remains understudied. This article provides the first record of the distribution of Alcyonacea on the shallow fringing reefs around Antsiranana Bay, northern Madagascar. Alcyonacea accounted for between one and 16 % of the reef benthos surveyed; 11 genera belonging to four families, and several unidentified gorgonians (sea fans were recorded. Abundant and diverse Alcyonacea assemblages were recorded on reefs that were exposed with high water clarity. However, abundant and diverse communities were also observed on sheltered reefs with low water clarity, high sediment cover and relatively low hard coral cover, implying potential competitive advantage under these conditions. Where prevailing environmental conditions were relatively moderate, the Alcyonacea assemblages were generally characterised by low diversity and an abundance of Sinularia and Sarcophyton. Because of the current lack of knowledge about the coral reefs in Antsiranana Bay, it was not possible to suggest any appropriate management actions. We propose that this account should be built upon with similar studies of other reef taxa. This series would address the paucity of published information from this part of the western Indian Ocean, and would provide the baseline information necessary to inform future management plans for the area.

  5. Sub-decadal turbidite frequency during the early Holocene: Eel Fan, offshore northern California

    Science.gov (United States)

    Paull, Charles K.; McGann, Mary L.; Sumner, Esther J; Barnes, Philip M; Lundsten, Eve M; Anderson, Krystle; Gwiazda, Roberto; Edwards, Brian D.; Caress, David W

    2014-01-01

    Remotely operated and autonomous underwater vehicle technologies were used to image and sample exceptional deep sea outcrops where an ∼100-m-thick section of turbidite beds is exposed on the headwalls of two giant submarine scours on Eel submarine fan, offshore northern California (USA). These outcrops provide a rare opportunity to connect young deep-sea turbidites with their feeder system. 14C measurements reveal that from 12.8 ka to 7.9 ka, one turbidite was being emplaced on average every 7 yr. This emplacement rate is two to three orders of magnitude higher than observed for turbidites elsewhere along the Pacific margin of North America. The turbidites contain abundant wood and shallow-dwelling foraminifera, demonstrating an efficient connection between the Eel River source and the Eel Fan sink. Turbidite recurrence intervals diminish fivefold to ∼36 yr from 7.9 ka onward, reflecting sea-level rise and re-routing of Eel River sediments.

  6. Deep-water Fan Systems and Petroleum Resources on the Northern Slope of the South China Sea

    Institute of Scientific and Technical Information of China (English)

    PANG Xiong; YANG Shaokun; ZHU Ming; LI Jinsong

    2004-01-01

    The shallow shelf delta/strand arenaceous-pelitic deposit region in the north of the Pearl River mouth basin,sitting on the northern continental shelf of the South China Sea, has already become an important oil production base in China. Recent researched has revealed that a great deal of deep-water fans of great petroleum potentiality exist on the Baiyun deep-water slope below the big palco Pearl River and its large delta. Based on a mass of exploration wells and 2-D seismic data of the shallow shelf region, a interpretation of sequence stratigraphy confirmed the existence of deep-water fans. The cyclic falling of sea level, abundant detrital matter from the paleo Pearl River and the persistent geothermal subsidence in the Baiyun sag are the three prerequisites for the formation and development of deep-water fans. There are many in common between the deep-water shelf depositional system of the northern South China Sea and the exploration hotspots region on the two banks of the Atlantic. For example, both are located on passive continent margins, and persistent secular thermal subsidence and large palco rivers have supplied abundant material sources and organic matter.More recently, the discovery of the big gas pool on the northern slope of the Baiyun sag confirms that the Lower Tertiary lacustrine facies in the Baiyun sag has a great potentiality of source rocks. The fans overlying the Lower Tertiary source rocks should become the main exploration areas for oil and gas resources.

  7. A Field Study of Wall Furnace Venting and Coincident Exhaust Fan Usage in 16 Northern California Apartments

    Energy Technology Data Exchange (ETDEWEB)

    Singer, Brett C. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Less, Brennan D. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Delp, William W. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Brooks, Andrew [Association for Energy Affordability, Emeryville, CA (United States); Cohn, Sebastian [Association for Energy Affordability, Emeryville, CA (United States); Finn, Brian [Association for Energy Affordability, Emeryville, CA (United States)

    2016-09-01

    To inform efforts to improve combustion appliance testing in residential energy efficiency programs, we studied the frequency of coincident fan use and depressurization-induced downdrafting and spillage from atmospherically vented (i.e., natural draft) wall furnaces in airtight apartments. Indoor environmental conditions, heating appliance operation, use of exhaust fans, and cooking with stovetop or oven were monitored for approximately three weeks each in 16 apartment units in two buildings in Northern California. Apartments also were assessed using standard combustion appliance safety test methods and enhanced protocols. Monitoring occurred in February and March of 2016, with heating demand corresponding to 7.3 ± 0.5 heating degree-days at a 65ºF reference temperature. Most of the furnaces spilled combustion products when the apartments were depressurized in the “worst-case” challenge condition of all exhaust fans operating at their highest settings and all windows closed. Many also spilled under less challenging conditions (e.g., with kitchen exhaust fan on low and bathroom fan operating). On average, bathroom exhaust fans were operated 3.9% of monitored minutes (13.5% max), and cooking (burner or kitchen fan operation) occurred 4.6% of minutes (max 13.3%). Event lengths averaged 17 minutes (max 540) and 34 minutes (max 324), respectively. Their coincident operation averaged 0.34% of minutes (max 2.0%), with average event length of 13 minutes (max 92 minutes). This suggests that the operation of apartment units at or near the currently used worst-case challenge condition is quite rare. Wall furnace burners operated an average of 2.8% of minutes (max of 8.9%), with average burner cycle length of 14 minutes (max 162). Coincident bath fan use, cooking and wall furnace operation was very rare, occurring only a handful of times across all apartments. The highest rate was 0.075% of monitored minutes in one apartment, and the longest event length was 12 minutes

  8. Quaternary alluvial fans of Ciudad Juárez, Chihuahua, northern México: OSL ages and implications for climatic history of the region

    Science.gov (United States)

    Zúñiga de León, David; Kershaw, Stephen; Mahan, Shannon

    2016-01-01

    Alluvial fans formed from sediments derived from erosion of the Juárez Mountains in northernmost México have a significant flood impact on the Ciudad Juárez, which is built on the fan system. The northern part of Ciudad Juárez is the most active; further south, older parts of the fan, upon which the rest of the city is built, were largely eroded by natural processes prior to human habitation and subsequently modified only recently by human construction. Three aeolian sand samples, collected from the uppermost (youngest) parts of the fan system in the city area, in places where human intervention has not disturbed the sediment, and constrain the latest dates of fan building. Depositional ages of the Quaternary alluvial fans were measured using Optically Stimulated Luminescence (OSL) on aeolian sands that have inter-fingered with alluvial fan material. These dates are: a) sample P1, 31 ka; b) sample P2, 41 ka; c) sample P3, 74 ka, between Oxygen Isotope Stages (OIS) 3 to 5. They demonstrate that fan development, in the area now occupied by the city, terminated in the Late Pleistocene, immediately after what we interpret to have been an extended period of erosion without further deposition, lasting from the Late Pleistocene to Holocene. The three dates broadly correspond to global glacial periods, implying that the cool, dry periods may reflect periods of aeolian transport in northern México in between phases that were wetter to form the alluvial fans. Alluvial fan margins inter-finger with fluvial terrace sediments derived from the Río Bravo, indicating an additional component of fan dissection by Río Bravo lateral erosion, presumed to be active during earlier times than our OSL ages, but these are not yet dated. Further dating is required to ascertain the controls on the fan and fluvial system.

  9. Classification and Evolution of Deep Water Channels at Block A in Miocene Congo Fan, Lower Congo Basin%西非下刚果盆地刚果扇A区块中新统深水水道分类及演化

    Institute of Scientific and Technical Information of China (English)

    熊浩浩; 王振奇; 付欢; 郑勇; 贺小林

    2014-01-01

    以高精度三维地震资料为基础,结合深水水道成因机制和水道截面形态特征,将下刚果盆地A区块中新统深水水道分为侵蚀型、侵蚀加积型和加积型三类,并进一步细分为九种亚类。该分类体现了A区块深水水道从近源至远源方向的横向展布特征。从近源至远源,流体动力条件逐渐减弱,水道形态演化过程为限制性-非限制性-限制性-前端朵叶,水道宽深比和弯曲度均逐渐变大。通过对每个三级层序均方根振幅属性图的分析,并结合海平面升降和构造抬升作用,可见刚果扇不断由南向北迁移及向盆地方向进积,层序自下而上并由南向北,整体由加积水道和远端朵叶沉积向侵蚀加积水道和侵蚀水道沉积转变。%Combined with high-resolution three-dimensional seismic data and the genetic mechanism of deep-water channels and the morphology of channel cross-sections at the studied Block A in Miocene Congo fan, Lower Congo Basin, it is shown that the deep-water channels can be divided into erosional, erosion-aggradational and aggradational channels, which can be further divided into nine subtypes. This classification indicates the lateral variations of these deep water channels from proximal to distal source at the Block A. From proximal to distal source, the channels display an evolutional process in morphology along with the hydrodynamic condition of these channels gradually decreases, that is, from limit, through unlimit and limit, to frontal splay, which results in the width/depth ratio and the sinuosity of the channels gradually increase. Based on the RMS amplitude diagram of per third-order sequence, considering of both sea level changes and tectonic uplift, it is claimed that the Miocene Congo fan migrates from south to north, and progresses toward the basin. The whole sedimentary sequence represent, from lower to upper and from south to north, that the aggradational channel and

  10. Large Vesicomyidae (Mollusca: Bivalvia) from cold seeps in the Gulf of Guinea off the coasts of Gabon, Congo and northern Angola

    Science.gov (United States)

    von Cosel, Rudo; Olu, Karine

    2009-12-01

    Two new genera and three new species of large Vesicomyidae are described from cold-seep sites on pockmarks and other sulfide-rich environments in the Gulf of Guinea (tropical east Atlantic) off Gabon, Congo (Brazzaville) and northern Angola, from 500 to 4000 m depth: " Calyptogena" (s.l.) regab n. sp., Wareniconcha (n.g.) guineensis (Thiele and Jaeckel 1931), Elenaconcha guiness n.g. n. sp., and Isorropodon atalantae n. sp. For two other species already taken by the R/V Valdivia in 1898, Calyptogena valdiviae (Thiele and Jaeckel 1931) and Isorropodon striatum (Thiele and Jaeckel 1931) new localities were discovered, and the species are rediscussed. E. guiness n.g. n.sp. is also recorded from off Banc d'Arguin, Mauritania, collected by commercial fishing vessels. The vesicomyid species here treated were encountered in different depth ranges along the Gabon-Congo-Angola margin, between 500 and 4000 m depth, and it was found that, in comparison with the dredge samples taken by the Valdivia expedition off southern Cameroon and off Rio de Oro (both at 2500 m), the same species occur in other depth ranges, in some cases with a vertical difference of more than 1000 m. .That means that the species are not confined to a given depth thought being typical for them and that the characteristics of the biotope are likely to play a major role in the distribution of the vesicomyids associated to cold seeps or other reduced environments along the West African margin.

  11. Submarine fans and associated deposits in the lower Tertiary of Guipuzcoa (Northern Spain)

    NARCIS (Netherlands)

    Vliet, van A.

    1982-01-01

    The Lower Tertiary outcrop along the coast of Guipuzcoa, northern Spain, consists exclusively of deep-marine sediments, deposited in a narrow elongated (ESE-WNW) basin. The early Tertiary sedimentary history of this basin can be described in terms of three main phases:- a phase of predominantly (hem

  12. Associated fauna of the fan shell Pinna nobilis (Mollusca: Bivalvia in the northern and eastern Tunisian coasts

    Directory of Open Access Journals (Sweden)

    Lotfi Rabaoui

    2009-03-01

    Full Text Available Epifaunal communities associated with the fan shell Pinna nobilis Linnaeus, 1758 along the Tunisian coastline were investigated. Both univariate and multivariate analysis were done at different spatial scales within five populations located at different localities, three from northern and two from eastern Tunisia. The size of Pinna did not appear as the main factor affecting the structure of the associated biota, which seemed to be more influenced by (a marine-lagoon and (b biogeographic gradients. Patterns of similarity of sessile sclerobionts and motile epifauna were clearly different. The former assemblage best replied to lagoon-sea gradient and to locality, with three real clusters at 40%, whereas the latter assemblage scattered widely in a non-metrical MDS plane, with two real clusters only at 20% similarity. The spatial turnover of motile species was ten times higher than that of sessile species at a small spatial scale, being less affected by Pinna size, and three times higher though invariant at a large geographic scale. On the other hand, β-diversity of sessile species appeared to be more influenced by latitudinal (climatic gradient at a large scale, being higher in the northern than in the eastern communities. Analysis of taxonomic (dissimilarity of the whole community detected these two sources of environmental (lagoon-sea gradient and biogeographic (lati-longitudinal gradient variation, although each phylum showed its peculiar pattern. In terms of Dajoz’s constancy index the majority of associated communities were dominated by rare species, and within the majority of epifaunal assemblages, the most abundant sessile epizoobiont was a bivalve mollusc. The sessile epifauna was dominated by active filterers, which led to a possible existence of trophic competition between the host and the sedentary epizoites, since both basibionts and sclerobionts occupy the same trophic niche. The fan shell played an important ecological role

  13. Q emocratic Republic of the Congo:

    African Journals Online (AJOL)

    Women and Peace-building in the Democratic Republic of the Congo .... Former Yugoslavia, Burundi, Northern Ireland and India and Pakistan. In the ..... we would have thought it was time to talk about sexual violence against women.

  14. New morpho-stratigraphic constraints for the evolution of the alluvial fan system along the northern slopes of the Taburno-Camposauro Mountains (Calore River basin, Southern Italy)

    Science.gov (United States)

    Leone, Natalia; Amato, Vincenzo; Aucelli, Pietro P. C.; Cesarano, Massimo; Filocamo, Francesca; Petrosino, Paola; Rosskopf, Carmen M.; Valente, Ettore; Giralt, Santiago; Casciello, Emilio

    2016-04-01

    The Lower Calore River Valley is a morphostructural depression located in the inner sector of the Campanian Apennine, between the Taburno-Camposauro and the Matese carbonate massifs. The river is the main left tributary of the Volturno River, it has a meandering channel partially structural-controlled. Numerous morphotectonic clues and historical seismicity data suggest that this part of the Apennine chain was particularly active during the late-Quaternary. In detail, the valley is E-W oriented and presents an asymmetry of the opposed valley slopes. The left side, corresponding to the northern flank of the Camposauro massif, is characterized by a steep slope (70°-35°), partially controlled by a ~E-W oriented fault system, and by a wide less-inclined piedmont aggradation zone. The latter started growing since middle Pleistocene, with the deposition of alluvial fans and slope deposits over the well cemented early Pleistocene breccias of Laiano Synthem. The alluvial fan deposition has been active until present giving rise to three main generations of alluvial fans. The right side of the valley, instead, is characterized by seven orders of fluvial terraces, both of erosional and depositional origin. The quaternary morpho-stratigraphic evolution of alluvial fans and fluvial terraces has been strongly conditioned by the interaction of tectonic phases and climatic variations. A detailed geomorphological study (1:5.000 in scale) was carried out with the aim to map the main depositional and erosional fluvial landforms and to identify the main tectonic lineaments of the area. A detailed field survey allowed to better define the stratigraphic and paleoenvironmental context in which the alluvial deposits developed and also to find chrono-stratigraphic markers. Tephra-stratigraphic analyses were performed on pyroclastic deposits interbedded into the alluvial fan and fluvial successions. At the moment the age of the first generation of alluvial fans is still under

  15. On Intensive Late Holocene Iron Mining and Production in the Northern Congo Basin and the Environmental Consequences Associated with Metallurgy in Central Africa

    Science.gov (United States)

    Lupo, Karen D.; Schmitt, Dave N.; Kiahtipes, Christopher A.; Ndanga, Jean-Paul; Young, D. Craig; Simiti, Bernard

    2015-01-01

    An ongoing question in paleoenvironmental reconstructions of the central African rainforest concerns the role that prehistoric metallurgy played in shaping forest vegetation. Here we report evidence of intensive iron-ore mining and smelting in forested regions of the northern Congo Basin dating to the late Holocene. Volumetric estimates on extracted iron-ore and associated slag mounds from prehistoric sites in the southern Central African Republic suggest large-scale iron production on par with other archaeological and historically-known iron fabrication areas. These data document the first evidence of intensive iron mining and production spanning approximately 90 years prior to colonial occupation (circa AD 1889) and during an interval of time that is poorly represented in the archaeological record. Additional site areas pre-dating these remains by 3-4 centuries reflect an earlier period of iron production on a smaller scale. Microbotanical evidence from a sediment core collected from an adjacent riparian trap shows a reduction in shade-demanding trees in concert with an increase in light-demanding species spanning the time interval associated with iron intensification. This shift occurs during the same time interval when many portions of the Central African witnessed forest transgressions associated with a return to moister and more humid conditions beginning 500-100 years ago. Although data presented here do not demonstrate that iron smelting activities caused widespread vegetation change in Central Africa, we argue that intense mining and smelting can have localized and potentially regional impacts on vegetation communities. These data further demonstrate the high value of pairing archeological and paleoenvironmental analyses to reconstruct regional-scale forest histories. PMID:26161540

  16. On Intensive Late Holocene Iron Mining and Production in the Northern Congo Basin and the Environmental Consequences Associated with Metallurgy in Central Africa.

    Directory of Open Access Journals (Sweden)

    Karen D Lupo

    Full Text Available An ongoing question in paleoenvironmental reconstructions of the central African rainforest concerns the role that prehistoric metallurgy played in shaping forest vegetation. Here we report evidence of intensive iron-ore mining and smelting in forested regions of the northern Congo Basin dating to the late Holocene. Volumetric estimates on extracted iron-ore and associated slag mounds from prehistoric sites in the southern Central African Republic suggest large-scale iron production on par with other archaeological and historically-known iron fabrication areas. These data document the first evidence of intensive iron mining and production spanning approximately 90 years prior to colonial occupation (circa AD 1889 and during an interval of time that is poorly represented in the archaeological record. Additional site areas pre-dating these remains by 3-4 centuries reflect an earlier period of iron production on a smaller scale. Microbotanical evidence from a sediment core collected from an adjacent riparian trap shows a reduction in shade-demanding trees in concert with an increase in light-demanding species spanning the time interval associated with iron intensification. This shift occurs during the same time interval when many portions of the Central African witnessed forest transgressions associated with a return to moister and more humid conditions beginning 500-100 years ago. Although data presented here do not demonstrate that iron smelting activities caused widespread vegetation change in Central Africa, we argue that intense mining and smelting can have localized and potentially regional impacts on vegetation communities. These data further demonstrate the high value of pairing archeological and paleoenvironmental analyses to reconstruct regional-scale forest histories.

  17. On Intensive Late Holocene Iron Mining and Production in the Northern Congo Basin and the Environmental Consequences Associated with Metallurgy in Central Africa.

    Science.gov (United States)

    Lupo, Karen D; Schmitt, Dave N; Kiahtipes, Christopher A; Ndanga, Jean-Paul; Young, D Craig; Simiti, Bernard

    2015-01-01

    An ongoing question in paleoenvironmental reconstructions of the central African rainforest concerns the role that prehistoric metallurgy played in shaping forest vegetation. Here we report evidence of intensive iron-ore mining and smelting in forested regions of the northern Congo Basin dating to the late Holocene. Volumetric estimates on extracted iron-ore and associated slag mounds from prehistoric sites in the southern Central African Republic suggest large-scale iron production on par with other archaeological and historically-known iron fabrication areas. These data document the first evidence of intensive iron mining and production spanning approximately 90 years prior to colonial occupation (circa AD 1889) and during an interval of time that is poorly represented in the archaeological record. Additional site areas pre-dating these remains by 3-4 centuries reflect an earlier period of iron production on a smaller scale. Microbotanical evidence from a sediment core collected from an adjacent riparian trap shows a reduction in shade-demanding trees in concert with an increase in light-demanding species spanning the time interval associated with iron intensification. This shift occurs during the same time interval when many portions of the Central African witnessed forest transgressions associated with a return to moister and more humid conditions beginning 500-100 years ago. Although data presented here do not demonstrate that iron smelting activities caused widespread vegetation change in Central Africa, we argue that intense mining and smelting can have localized and potentially regional impacts on vegetation communities. These data further demonstrate the high value of pairing archeological and paleoenvironmental analyses to reconstruct regional-scale forest histories.

  18. Seismic waveform inversion and imaging of deepwater glacial sedimentary fans in the northern Norwegian-Greenland Sea

    Science.gov (United States)

    Libak, Audun; Poor Moghaddam, Peyman; Minakov, Alexander; Ruud, Bent Ole; Keers, Henk; Mjelde, Rolf

    2013-04-01

    In this poster we show results from 2D acoustic pre-stack depth migration and full waveform inversion using multichannel seismic data, complemented by coincident travel-time tomography of wide-angle ocean bottom seismometer data. The study area is located within the deep ocean basin in the northeastern parts of the Norwegian-Greenland Sea. This area was affected by intense Quaternary glacial sedimentation in the Storfjorden and Bjørnøya Fans and formation of submarine mega-slides. The seismic source used for the data acquisition consisted of an array of six airguns, and the wavefield was recorded by a 3-km-long 240-channel streamer. After some initial processing, pre-stack depth migration and waveform inversion was performed in order to obtain an image the glacial sedimentary package. The background velocity model was obtained from travel time tomography on the coincident ocean bottom seismometer data. We first show inversion results for a test model which is based on the our knowledge of the geology of the area. We then show the inversion results on the real data. One of the main differences between the test inversion and the real data inversion is the inknown source wavelet in the latter case. We show how the source wavelet affects the inversion results and how to properly take the source wavelet into account.

  19. Provenance of a large Lower Cretaceous turbidite submarine fan complex on the active Laurasian margin: Central Pontides, northern Turkey

    Science.gov (United States)

    Akdoğan, Remziye; Okay, Aral I.; Sunal, Gürsel; Tari, Gabor; Meinhold, Guido; Kylander-Clark, Andrew R. C.

    2017-02-01

    The Pontides formed the southern active margin of Laurasia during the Mesozoic. They became separated from mainland Laurasia during the Late Cretaceous, with the opening of the Black Sea as an oceanic back-arc basin. During the Early Cretaceous, a large submarine turbidite fan complex developed in the Central Pontides. The turbidites cover an area of 400 km by 90 km with a thickness of more than 2 km. We have investigated the provenance of these turbidites-the Çağlayan Formation-using paleocurrent measurements, U-Pb detrital zircon ages, REE abundances of dated zircons and geochemistry of detrital rutile grains. 1924 paleocurrent measurements from 96 outcrop stations indicate flow direction from northwest to southeast in the eastern part of the Çağlayan Basin and from north-northeast to west-southwest in the western part. 1194 detrital zircon ages from 13 Lower Cretaceous sandstone samples show different patterns in the eastern, central and western parts of the basin. The majority of the U-Pb detrital zircon ages in the eastern part of the basin are Archean and Paleoproterozoic (61% of all zircon ages, 337 grains); rocks of these ages are absent in the Pontides and present in the Ukrainian Shield, which indicates a source north of the Black Sea. In the western part of the basin the majority of the zircons are Carboniferous and Neoproterozoic (68%, 246 grains) implying more local sources within the Pontides. The detrital zircons from the central part show an age spectrum as mixture of zircons from western and eastern parts. Significantly, Jurassic and Early Cretaceous zircons make up less than 2% of the total zircon population, which implies lack of a coeval magmatic arc in the region. This is compatible with the absence of the Lower Cretaceous granites in the Pontides. Thus, although the Çağlayan Basin occupied a fore-arc position above the subduction zone, the arc was missing, probably due to flat subduction, and the basin was largely fed from the Ukrainian

  20. Morphology, structure, composition and build-up processes of the active channel-mouth lobe complex of the Congo deep-sea fan with inputs from remotely operated underwater vehicle (ROV) multibeam and video surveys

    Science.gov (United States)

    Dennielou, Bernard; Droz, Laurence; Babonneau, Nathalie; Jacq, Céline; Bonnel, Cédric; Picot, Marie; Le Saout, Morgane; Saout, Yohan; Bez, Martine; Savoye, Bruno; Olu, Karine; Rabouille, Christophe

    2017-08-01

    The detailed structure and composition of turbiditic channel-mouth lobes is still largely unknown because they commonly lie at abyssal water depths, are very thin and are therefore beyond the resolution of hull-mound acoustic tools. The morphology, structure and composition of the Congo turbiditic channel-mouth lobe complex (90×40 km; 2525 km2) were investigated with hull-mounted swath bathymetry, air gun seismics, 3.5 kHz sub-bottom profiler, sediment piston cores and also with high-resolution multibeam bathymetry and video acquired with a Remote Operating Vehicle (ROV). The lobe complex lies 760 km off the Congo River mouth in the Angola abyssal plain between 4740 and 5030 m deep. It is active and is fed by turbidity currents that deposit several centimetres of sediment per century. The lobe complex is subdivided into five lobes that have prograded. The lobes are dominantly muddy. Sand represents ca. 13% of the deposits and is restricted to the feeding channel and distributaries. The overall lobe body is composed of thin muddy to silty turbidites. The whole lobe complex is characterized by in situ mass wasting (slumps, debrites). The 1-m-resolution bathymetry shows pervasive slidings and block avalanches on the edges of the feeding channel and the channel mouth indicating that sliding occurs early and continuously in the lobe build-up. Mass wasting is interpreted as a consequence of very-high accumulation rates, over-steepening and erosion along the channels and is therefore an intrinsic process of lobe building. The bifurcation of feeding channels is probably triggered when the gradient in the distributaries at the top of a lobe becomes flat and when turbidity currents find their way on the higher gradient on the lobe side. It may also be triggered by mass wasting on the lobe side. When a new lobe develops, the abandoned lobes continue to collect significant turbiditic deposits from the feeding channel spillover, so that the whole lobe complex remains active. A

  1. Crimean-Congo Haemorrhagic Fever

    Science.gov (United States)

    ... Questions & answers Features Multimedia Contacts Crimean-Congo haemorrhagic fever Fact sheet N°208 January 2013 Key facts ... the principal tick vector. The Crimean-Congo haemorrhagic fever virus in animals and ticks The hosts of ...

  2. Cannibalism in Colonial Congo

    OpenAIRE

    Lindholm, Anders; Gehin, Laurent; Bliddal, Marie; Christensen, Josefine; Mauritzen, Alexandra

    2009-01-01

    The aim of the project is to view the different concepts of cannibalism seen in colonial Congo. By analyzing the meaning of cannibalism in Congo in the time span between 1890-1905, we have tried to find a coherence between cannibalism in its definitive and metaphorical form. Additionally we have attempted to determine whether cannibalism was more a myth than fact, and what impact it had on the natives. We have furthermore tried to put cannibalism in relation to contemporary fiction of the tim...

  3. Ky Fan inequalities

    CERN Document Server

    Moslehian, Mohammad Sal

    2011-01-01

    There are several inequalities in the literature carrying the name of Ky Fan. We survey these well-known Ky Fan inequalities and some other significant inequalities generalized by Ky Fan and review some of their recent developments.

  4. A method to assess fluvial fan channel networks, with a preliminary application to fans in coastal British Columbia

    Science.gov (United States)

    Millard, Thomas Hugh; Hogan, Dan L.; Wilford, David J.; Roberts, Brian

    2010-03-01

    The channel network on a fluvial fan distributes sediment across the fan surface and determines fan development. We present a method to characterize fan channel networks (FCNs) so that the effect of controls (e.g., sediment supply) on the FCN can be evaluated. We then do a preliminary test of the method using three fans in coastal British Columbia. The method uses a set of three measures: 1) the spatial extent of hydrogeomorphic activity, measured as the percentage of the contemporary fan surface area occupied by active channels; 2) the topologic structure, using node counts to measure channel network complexity; and 3) a sediment budget to indicate the proportion of sediment that is stored on the fan, loosely characterized by comparing the second-largest clast size of sediment at the fan apex or intersection point with the second-largest clast at the toe of the fan. These measures were applied to two fan deltas and one partial fan delta in northern Vancouver Island, British Columbia, using channel surveys conducted in 2006 and 2007. All three fans are located within 30 km of each other, have similar climatic, physiographic, and vegetation settings, and have natural channel networks. Each fan has perennial channel flow at the fan apex. Watershed areas range from 19.5 to 35.6 km 2, and contemporary fan areas range from 0.2 to 0.7 km 2. The Melton Relative Relief ratio ranges from 0.24 to 0.30 and none of the fans show evidence of debris floods or debris flows. In addition to testing the efficacy of the FCN measures, we use these fans to explore the question of whether fans in similar geomorphic settings and with similar controls develop similar FCNs. Results show the fans have between 4.7-8.5 % of the contemporary fan surface occupied by the active channel network. Topologic node counts indicate that the two fan deltas have a similar level of channel complexity, with 42-54 nodes in total. The partial fan delta channel network is approximately half as complex, with

  5. Breeding the Congo Peacock

    NARCIS (Netherlands)

    Bemmel, van A.C.V.

    1961-01-01

    The discovery of the Congo Peacock (Afropavo congensis CHAPIN) is one of the most recent in ornithology. Certainly it is the most famous one. The history of the discovery has been described by CHAPIN in detail (5, 6). The first living specimens exported from Kongo reached the United States June 1949

  6. Breeding the Congo Peacock

    NARCIS (Netherlands)

    Bemmel, van A.C.V.

    1961-01-01

    The discovery of the Congo Peacock (Afropavo congensis CHAPIN) is one of the most recent in ornithology. Certainly it is the most famous one. The history of the discovery has been described by CHAPIN in detail (5, 6). The first living specimens exported from Kongo reached the United States June

  7. An Interview with Fan Wu

    Institute of Scientific and Technical Information of China (English)

    李娜

    2006-01-01

    Fan Wu grew up on a farm in South China, in the community to where her parents were exiled during the Cultural Revolution (1966-1976). Wu moved to the United States in 1997, to attend Stanford University, and she began writing in 2002. She now lives and works in northern California, the United State. February Flowers is her first novel. During her recent book tour in China, she took time to talk to Women of China. Women of China (WOC): What inspired

  8. Sources and distributions of branched and isoprenoid tetraether lipids on the Amazon shelf and fan: Implications for the use of GDGT-based proxies in marine sediments

    NARCIS (Netherlands)

    Zell, C.; Kim, J.H.; Hollander, D.; Lorenzoni, L.; Baker, P.; Guizan Silva, G.S.; Sinninghe Damsté, J.S.

    2014-01-01

    Branched glycerol dialkyl glycerol tetraethers (brGDGTs) in river fan sediments have been used successfully to reconstruct mean annual air temperature (MAAT) and soil pH of the Congo River drainage basin. However, in a previous study of Amazon deep-sea fan sediments the reconstructed MAATs were ca.

  9. Composite fan stator assembly

    Energy Technology Data Exchange (ETDEWEB)

    Donges, G.L.

    1993-07-13

    A composite fan stator assembly is described for a gas turbine engine having at least two fan rotor stages, the composite stator assembly comprising: an annular composite fan case assembly including an access port, the fan case assembly circumferentially disposed around first and second fan rotor stage locations, a composite fan stator stage supported by and extending radially inward of the fan case assembly and axially disposed between the two fan rotor stage locations, the fan stator stage includes at least one removable vane segment accessible for removal through the access port for assembly and reassembly, the composite fan case assembly including a separable composite forward fan case assembly and a separable composite aft fan case assembly spaced axially aft of the forward fan case assembly, the forward fan case assembly being bolted to the aft fan case assembly, wherein the composite fan stator stage is axially and radially trapped and supported by the forward and aft fan case assemblies. A composite stator vane assembly comprising: a composite inner shroud, a composite outer shroud disposed radially outward of the inner shroud, a plurality of vanes disposed between the shrouds, the vanes including a suction side and a pressure side and radially inner and outer roots, the roots extending through platforms of corresponding ones of the inner and outer shrouds, four box-type attachment elements corresponding to curved suction and pressure sides of the inner and outer roots, the box-type attachment elements having two connected legs angled with respect to each other, a first one of the legs extending along, conforming to the curve of, and bonded to a corresponding one of the airfoil root sides, and a second one of the legs extending along and bonded to a composite shroud surface.

  10. Looking closer at the Congo

    DEFF Research Database (Denmark)

    Jansson, Johanna; Jiang, Wenran

    2011-01-01

    An NGO report on Chinese investment in the Democratic Republic of Congo opens a vital debate, but its methodology leaves the reader wanting a fuller version of the facts, write Johanna Jansson and Jiang Wenran.......An NGO report on Chinese investment in the Democratic Republic of Congo opens a vital debate, but its methodology leaves the reader wanting a fuller version of the facts, write Johanna Jansson and Jiang Wenran....

  11. High pressure axial flow fans for modern coal power stations

    Energy Technology Data Exchange (ETDEWEB)

    Cyrus, Vaclav [AHT Energetika s.r.o., Praha (Czech Republic); Koci, Petr [ZVVZ Milevsko a.s. (Czech Republic)

    2008-07-01

    Brown coal fired power stations, located in Northern Bohemia, have mostly older boiler blocks with an output of 110 and 200 MWe. Flue gases are cleaned by the desulphurization plants installed between 1993 and 1997. Usually, each boiler block has two air fans and one to three flue gas fans. Flue gas fans operate in severe conditions; fan blades should be resistant to the flue gases containing sulphur and acid drops with the operating temperature at 170 C to 190 C. Additionally, flue gas also often contains ash particles. Currently, some boiler blocks are gradually being refurbished. New blocks with an electrical power output of 600 to 700 MWe are at the design stage. Submitted paper shows our design study of one stage axial flow fan for the new blocks. Results from the new aerodynamic research of the axial flow stages were used in the fan design. (orig.)

  12. Crimean-Congo Hemorrhagic Fever (CCHF)

    Science.gov (United States)

    ... Cancel Submit Search The CDC Crimean-Congo Hemorrhagic Fever (CCHF) Note: Javascript is disabled or is not ... on Facebook Tweet Share Compartir Crimean-Congo hemorrhagic fever (CCHF) is caused by infection with a tick- ...

  13. Solar powered headwear fan

    Energy Technology Data Exchange (ETDEWEB)

    Hirsh, G.B.; Volk, S.; Cirrito, W.; Brann, D.

    1987-07-21

    A fan assembly is described. A housing is adapted for resting on an exterior surface of headwear. A fan mounted in the housing at one end of the housing is adapted for forcing air through an opening defined in a forward protuberance of the headwear. Solar cell means are mounted on the housing at another end of the housing opposite to and remote from the one end for powering the fan means and adapted for resting on a crown of the headwear. Vent means are defined by the housing for allowing air to be sucked into the housing and forced out of the housing when the power means drive the fan means. Mounting means are defined by the housing, including hinge means for removably mounting the modular fan assembly on an exterior surface of the headwear. A portion of the housing occupies a substantial distance between the fan means and the solar cell means. Display means are defined by the portion of the housing between the power means and the fan means for displaying of decorative graphic material.

  14. Fatness and muscularity as risk indicators of child mortality in rural Congo

    NARCIS (Netherlands)

    J. van den Broeck; R. Eeckels; A.C.S. Hokken-Koelega (Anita)

    1998-01-01

    textabstractOBJECTIVES: To examine the relationship of anthropometrical indicators of fatness and muscularity with mortality in children in a rural African community. BACKGROUND: A prospective cohort study was carried out in the rural health zone of Bwamanda, Northern Congo using a

  15. Salt tectonics and its relationship to hydrocarbon accumulation in salt basins with a lower rifted section and an upper continental marginal section:A case study of the Lower Congo-Congo Fan basins and the Kwanza Basin in West Africa%裂谷与被动陆缘叠合盆地的盐构造与油气成藏——以西非下刚果—刚果扇盆地和宽扎盆地为例

    Institute of Scientific and Technical Information of China (English)

    孙自明; 何治亮

    2016-01-01

    西非海岸的加蓬、下刚果—刚果扇和宽扎等盆地均为典型的裂谷与被动陆缘叠合含盐含油气盆地,经历了裂谷期(早白垩世凡兰吟期—巴列姆期)、过渡期(阿普第期—早阿尔必期)和被动陆缘期(早白垩世阿尔必期—现今)3个演化阶段,沉积了裂谷期陆相地层、过渡期蒸发岩和被动陆缘期海相地层3套地层层序.古近纪以来,受非洲大陆隆升和大西洋被动陆缘持续沉降的影响,以过渡期蒸发岩为滑脱层,形成了变形特征迥异的盐上和盐下构造变形层;前者为盖层滑脱型构造,变形强烈,盐构造样式类型多样,从陆向海具有明显的构造分带特征;后者属于基底卷入型构造,变形微弱,基本保持了裂谷盆地的原始构造面貌.盐构造变形不仅控制盐上层系储层发育和圈闭形成,而且盐岩层本身又是盐下层系良好的区域盖层,尤其是盐岩层急剧增厚的深水—超深水地区,客观上对盐下和盐上油气系统具有明显的分隔作用,即盐下层系生成的油气仅在盐下层系运移聚集;但在盐岩层厚度急剧减薄或缺失的浅水至陆上地区,盐窗发育,加之断裂的垂向沟通,盐下油气可以向盐上层系运移并聚集成藏.%The West African coastal basins, such as the Gabon Coastal Basin, Lower Congo Basin and Kwanza Ba?sin, are typical oil?bearing salt basins with a lower rifted section and an upper continental marginal section. Three evolution stages can be identified in those basins, including a rifting period ( the Early Cretaceous Valanginian to Barremian), a transitional period (Aptian to the early Albian) and a passive continental margin period (the early Cretaceous Albian to present), thus developing three tectono?sedimentary sequences from base to top: pre?salt, evaporites, and post?salt. On one hand, under the influence of the uplifting African craton and the continuing sub?sidence of the Atlantic passive margin from Paleogene to

  16. Submarine-fan facies associations of the Upper Cretaceous and Paleocene Gottero Sandstone, Ligurian Apennines, Italy

    Science.gov (United States)

    Nilsen, Tor H.; Abbate, Ernesto

    1984-06-01

    The Upper Cretaceous and Paleocene Gottero Sandstone was deposited as a small deep-sea fan on ophiolitic crust in a trench-slope basin. It was thrust northeastward as an allochthonous sheet in Early and Middle Cenozoic time. The Gottero, as thick as 1500 m, was probably derived from erosion of Hercynian granites and associated metamorphic rocks in northern Corsica. Outcrops of inner-fan channel, middle-fan channel and interchannel, outer-fan lobe, fan-fringe, and basin-plain facies associations indicate that the depositional model of Mutti and Ricci Lucchi for mixed-sediment deep-sea fans can be used. The original fan had a radius of 30 to 50 km.

  17. Characterizing subsurface hydraulic heterogeneity of alluvial fan using riverstage fluctuations

    Science.gov (United States)

    Wang, Yu-Li; Yeh, Tian-Chyi Jim; Wen, Jet-Chau; Huang, Shao-Yang; Zha, Yuanyuan; Tsai, Jui-Pin; Hao, Yonghong; Liang, Yue

    2017-04-01

    The objective of this study is to demonstrate the ability of riverstage tomography to estimate 2-D spatial distribution of hydraulic diffusivity (D) of Zhuoshui River alluvial fan, Taiwan, using groundwater level data from 65 wells and stream stage data from 5 gauging stations. In order to accomplish this objective, wavelet analysis is first conducted to investigate the temporal characteristics of groundwater level, precipitation, and stream stage. The results of the analysis show that variations of groundwater level and stream stage are highly correlated over seasonal and annual periods while that between precipitation is less significant. Subsequently, spatial cross-correlation between seasonal variations of groundwater level and riverstage data is analyzed. It is found that the correlation contour map reflects the pattern of sediment distribution of the fan. This finding is further substantiated by the cross-correlation analysis using both noisy and noise-free groundwater and riverstage data of a synthetic aquifer, where aquifer heterogeneity is known exactly. The ability of riverstage tomography is then tested with these synthetic data sets to estimate D distribution. Finally, the riverstage tomography is applied to the alluvial fan. The results of the application reveal that the apex and southeast of the alluvial fan are regions with relatively high D and the D values gradually decrease toward the shoreline of the fan. In addition, D at northern alluvial fan is slightly larger than that at southern. These findings are consistent with the geologic evolution of this alluvial fan.

  18. Bright Streaks and Dark Fans

    Science.gov (United States)

    2007-01-01

    The south polar region of Mars is covered every year by a layer of carbon dioxide ice. In a region called the 'cryptic terrain,' the ice is translucent and sunlight can penetrate through the ice to warm the surface below. The ice layer sublimates (evaporates) from the bottom. The dark fans of dust seen in this image come from the surface below the layer of ice, carried to the top by gas venting from below. The translucent ice is 'visible' by virtue of the effect it has on the tone of the surface below, which would otherwise have the same color and reflectivity as the fans. Bright streaks in this image are fresh frost. The CRISM team has identified the composition of these streaks to be carbon dioxide. Observation Geometry Image PSP_003113_0940 was taken by the High Resolution Imaging Science Experiment (HiRISE) camera onboard the Mars Reconnaissance Orbiter spacecraft on 26-Mar-2007. The complete image is centered at -85.8 degrees latitude, 106.0 degrees East longitude. The range to the target site was 244.9 km (153.0 miles). At this distance the image scale is 49.0 cm/pixel (with 2 x 2 binning) so objects 147 cm across are resolved. The image shown here has been map-projected to 50 cm/pixel . The image was taken at a local Mars time of 06:20 PM and the scene is illuminated from the west with a solar incidence angle of 79 degrees, thus the sun was about 11 degrees above the horizon. At a solar longitude of 207.6 degrees, the season on Mars is Northern Autumn.

  19. Fans af Bruce

    DEFF Research Database (Denmark)

    Vaaben, Nana Katrine

    2007-01-01

    Analysen viser, hvordan det samme ritual under en koncert forener og opdeler de fans, der orienterer sig mod Bruce Springsteen. På den ene side forener ritualet hele publikum i en stor fælles "Intimitet for mange" og på den anden side splitter det dem, fordi det bliver tydeligt, hvem der er de ri...

  20. What a Football Fan

    Institute of Scientific and Technical Information of China (English)

    王保安; 孙鹏

    2004-01-01

    While the football fan was thrilled to be at the Super Bowl, he was disappointed with the location of his seat. Peering across the stadium through his binoculars, he spied an empty seat on the 50-yard line and made his way there.

  1. 3D stratigraphic modeling of the Congo turbidite system since 210 ka: an investigation of factors controlling sedimentation

    Science.gov (United States)

    Laurent, Dimitri; Picot, Marie; Marsset, Tania; Droz, Laurence; Rabineau, Marina; Granjeon, Didier; Molliex, Stéphane

    2017-04-01

    The geometry and internal functioning of turbidite systems are relatively well-constrained today. However, the respective role of autogenic (topographic compensation, dynamics of turbidity currents…) and allogenic factors (tectonics, sea-level, climate) governing their architectural evolution is still under debate. The geometry of the Quaternary Congo Fan is characterized by successive sedimentary prograding/retrograding cycles bounded by upfan avulsions, reflecting a periodic control of sedimentation (Picot et al., 2016). Multi-proxy studies revealed a strong interplay between autogenic control and climate forcing as evidenced by changes in fluvial sediment supplies consistent with arid and humid periods in the Congo River Basin. In the light of these results, the aim of this study is to investigate the relative impact of internal and external forcing factors controlling, both in time and space, the formation and evolution of depocenters of the Congo Deep-Sea Fan since 210 ka. This work represents the first attempt to model in 3D the stratigraphic architecture of the Congo turbidite system using DionisosFlow (IFP-EN), a diffusion process-based software. It allows the simulation of sediment transport and the 3D geometry reproduction of sedimentary units based on physical processes such as sea level changes, tectonics, sediment supply and transport. According to the modeling results, the role of topographic compensation in the deep-sea fan geometry is secondary compared to climate changes in the drainage basin. It appears that a periodic variation of sediment discharge and water flow is necessary to simulate the timing and volume of prograding/retrograding sedimentary cycles and more particularly the upfan avulsion events. The best-fit simulations show that the overriding factor for such changes corresponds to the expansion of the vegetation cover in the catchment basin associated to the Milankovitch cycle of precession which controlled the West African Monsoon

  2. Observational Analysis of Coronal Fans

    Science.gov (United States)

    Talpeanu, D.-C.; Rachmeler, L; Mierla, Marilena

    2017-01-01

    Coronal fans (see Figure 1) are bright observational structures that extend to large distances above the solar surface and can easily be seen in EUV (174 angstrom) above the limb. They have a very long lifetime and can live up to several Carrington rotations (CR), remaining relatively stationary for many months. Note that they are not off-limb manifestation of similarly-named active region fans. The solar conditions required to create coronal fans are not well understood. The goal of this research was to find as many associations as possible of coronal fans with other solar features and to gain a better understanding of these structures. Therefore, we analyzed many fans and created an overview of their properties. We present the results of this statistical analysis and also a case study on the longest living fan.

  3. Fan Cart: The Next Generation

    Science.gov (United States)

    Lamore, Brian

    2016-10-01

    For years the fan cart has provided physics students with an excellent resource for exploring fundamental mechanics concepts such as acceleration, Newton's laws, impulse, momentum, work-energy, and energy conversions. The Physics Teacher has even seen some excellent do-it-yourself (DIY) fan carts and activities. If you are interested in developing the `E' portion of your and your students' STEM (science, technology, engineering, and math) skills, one way to accomplish this is to revisit the DIY fan cart. In this article I share a design of a new edition of the DIY fan cart and some ideas for incorporating the engineering design process into your high school curriculum.

  4. Dynamic and Implications of Football Fans' Club and Fans ...

    African Journals Online (AJOL)

    DrNneka

    Dross (2009) identified football games as one event that has proved potent ... have potential of drawing human attention to participate either as a player or as a ... However, beyond what football fans wears, the fans are sometimes ready to ...

  5. Skífan

    OpenAIRE

    Elín Ólafsdóttir

    2011-01-01

    Skífan er eina fyrirtækið hér á landi sem sérhæfir sig í sölu á tónlist, mynddiskum, tölvuleikjum og leikjatölvum. Sú atvinnugrein sem Skífan tilheyrir hefur fengið að finna töluvert fyrir þróun internetsins þar sem mögulegt er að hlaða þessu efni niður hvort sem er með löglegum eða ólöglegum hætti. Markmið verkefnisins var að skoða hver áhrif sviðsmynda væru á rekstrarlíkan Skífunnar. Höfundur fór í gegnum atvinnuvega- og samkeppnisgreiningu með aðstoð eiganda og rekstrarstjóra Skífunnar...

  6. Fan Cart: The Next Generation

    Science.gov (United States)

    Lamore, Brian

    2016-01-01

    For years the fan cart has provided physics students with an excellent resource for exploring fundamental mechanics concepts such as acceleration, Newton's laws, impulse, momentum, work-energy, and energy conversions. "The Physics Teacher" has even seen some excellent do-it-yourself (DIY) fan carts and activities. If you are interested…

  7. Optimisation of Fan Blade Angle

    Directory of Open Access Journals (Sweden)

    Swaroop M P

    2017-01-01

    Full Text Available This report represents the optimization of fan blade angle in accordance with the various room temperatures that can be in the tropical area like India. We took this work mainly because cooling is an important factor now a days in every area where construction and rooms are there and ceiling fans are the most common device that is commonly used. So it is of utmost importance to tweak the performance of this ceiling fan so that it can function in its most optimal condition. We have modeled the fan in a modeling software (SOLIDWORKS and imported that into an analyzing software (ANSYS and a result is generated on the various blade angles (0, 4, 8 and 12.5 degrees in accordance to room conditions. A trend line curve with the obtained data is expected as the result which can be crucial for designing of future fans

  8. Some geodynamic complexities related to the evolution of Bengal Fan and the neotectonic activity of the south Indian shield

    Digital Repository Service at National Institute of Oceanography (India)

    Murthy, K.S.R.

    After three decades of the International Indian Ocean Expedition (IIOE) and in spite of extensive geophysical data collected during the last one decade, the geodynamics of the Bengal Fan and the Peninsular shield at the northern end of the Indian...

  9. A history of RPGs: Made by fans; played by fans

    Directory of Open Access Journals (Sweden)

    Paul Mason

    2012-09-01

    Full Text Available I explore some aspects of the early history of tabletop role-playing games (RPGs that are perhaps not well known among media scholars, and which offer an alternative take on the idea of fan activity.

  10. 14 CFR 29.908 - Cooling fans.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Cooling fans. 29.908 Section 29.908... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant General § 29.908 Cooling fans. For cooling fans that are a part of a powerplant installation the following apply: (a) Category A. For cooling fans...

  11. Stranger than fiction: Fan identity in cosplay

    Directory of Open Access Journals (Sweden)

    Nicolle Lamerichs

    2011-09-01

    Full Text Available Academic accounts of fan cultures usually focus on creative practices such as fan fiction, fan videos, and fan art. Through these practices, fans, as an active audience, closely interpret existing texts and rework them with texts of their own. A practice scarcely examined is cosplay ("costume play", in which fans produce their own costumes inspired by fictional characters. Cosplay is a form of appropriation that transforms and actualizes an existing story in close connection to the fan community and the fan's own identity. I provide analytical insights into this fan practice, focusing on how it influences the subject. Cosplay is understood as a performative activity and analyzed through Judith Butler's concept of performativity. I specifically focus on boundaries between the body and dress, and on those between reality and fiction. I aim to show that cosplay emphasizes the personal enactment of a narrative, thereby offering new perspectives on fan identity.

  12. Football – Feminisation – Fans

    DEFF Research Database (Denmark)

    Mintert, Svenja-Maria

    the number of female fans in football has grown over the past years. A national sense of community, emotion and passion for the game is in particular reached during the international tournaments at live football spectacles and many female fans cheer and sing for ‘their’ team with the utmost conviction. Yet...... sociological theories. The objective is, first, to develop new knowledge and understanding about the impact of football on gendered identity construction and negotiation – in both the performance and the consumption of football – and how these female fans contribute to a European dialogue, the gender......-specific experience and acting out of fandom, and the intersection between gender and national/European identity. The second objective is to study the role of gender in football and fan cultures with regard to gender-specific patterns of cross-cultural communication and identification. The third objective...

  13. CPAFFC Delegation Visits Democratic Republic of the Congo and Republic of Congo

    Institute of Scientific and Technical Information of China (English)

    Xu; Liya

    2016-01-01

    At the invitation of Andre Kimbuta,mayor of Kinshasa in the Democratic Republic of the Congo,and Jean Marie Ewengue,mayor of Oyo city,Republic of Congo,a CPAFFC delegation led by Lin Yi,the group’s vice-president,visited the two countries from Sept 22 to 30.During the visit to the DRC,the delegation met with Edouard Mokolo

  14. On Some Generalized Ky Fan Minimax Inequalities

    Directory of Open Access Journals (Sweden)

    Luo Xianqiang

    2009-01-01

    Full Text Available Some generalized Ky Fan minimax inequalities for vector-valued mappings are established by applying the classical Browder fixed point theorem and the Kakutani-Fan-Glicksberg fixed point theorem.

  15. Advance Noise Control Fan II: Test Rig Fan Risk Management Study

    Science.gov (United States)

    Lucero, John

    2013-01-01

    Since 1995 the Advanced Noise Control Fan (ANCF) has significantly contributed to the advancement of the understanding of the physics of fan tonal noise generation. The 9'x15' WT has successfully tested multiple high speed fan designs over the last several decades. This advanced several tone noise reduction concepts to higher TRL and the validation of fan tone noise prediction codes.

  16. Crimean-Congo Hemorrhagic Fever, Sudan, 2008

    Centers for Disease Control (CDC) Podcasts

    2010-04-15

    This podcast describes the emergence of the first human cases of Crimean-Congo Hemorrhagic Fever in Sudan in 2008. CDC epidemiologist Dr. Stuart Nichol discusses how the disease was found in Sudan and how it spread in a hospital there.  Created: 4/15/2010 by National Center for Emerging and Zoonotic Infections (proposed).   Date Released: 4/15/2010.

  17. Cysticercosis in the Democratic Republic Of Congo

    Directory of Open Access Journals (Sweden)

    P. Dorny

    2012-06-01

    Full Text Available Cysticercosis, caused by Taenia solium eggs, is a zoonotic disease whose consequences can be severe especially in the cerebral localisation (neuorcysticercosis. Indeed, neurocysticercosis is the first cause of epilepsy amongst the infectious etiology group. Following the increase of epilepsy cases in Kinshasa and Bas-Congo, it was important to assess the fraction attributable to neurocysticercosis especially as data on cysticercosis in Democratic Republic Of Congo (DRC dating from 1970.A joint study between veterinary and human doctors was conducted in the provinces of Bas-Congo and Kinshasa between 2008 and 2010. Blood samples were collected from the general population, patients with epilepsy and pigs. These samples were analysed using ELISA antigen in the laboratory of the Institute of Tropical Medicine in Antwerp. Patients positive to ELISA antigen took the CT scan exam for the confirmation of neurocysticercosis. In the province of Kinshasa, of 530 epileptic patients, 6.3% were identified as neurocysticercosis cases. Out of a total of 498 pigs, 38.9% were positive for cysticercosis. In the province of Bas- Congo, of 943 inhabitants from Malanga village, 21.6% were positive with predominance in males (26.4% versus 17.5%. A total of 145 pigs from 5 villages were examined and 41.2% found positive.We can conclude that cysticercosis in the DRC has been neglected for a long time and cysticercosis could be a real major public health problem. Prospective studies addressing the consequences of cysticercosis in communities are needed in order to prevent epilepsy due to neurocysticercosis.

  18. Online Fan Fiction and Critical Media Literacy

    Science.gov (United States)

    Black, Rebecca W.

    2010-01-01

    This article explores English-language-learning (ELL) youths' engagement with popular media through composing and publicly posting stories in an online fan fiction writing space. Fan fiction is a genre that lends itself to critical engagement with media texts as fans repurpose popular media to design their own narratives. Analyses describe how…

  19. Fan/Ram Duct Program

    Science.gov (United States)

    1973-10-01

    mwm^mmmt c INPUT I ] H—f TRANSIENT ROUTINE P"" CONTROL """I FAN ] COMPRESSOR MAIN BURNER I DUCT HZ HIGH TURBINE in— LOW TURBINE I...and pressure ratio. 6. Low Turbine Low turbine characteristics, identical In form to those of the high turbine, are shown in figures 27 and 28. 7

  20. School Athletics and Fan Aggression

    Science.gov (United States)

    Bryan, Clifford; Horton, Robert

    1976-01-01

    Several hypotheses are developed regarding fans and their behavior based upon a review of the literature. An exploratory study is then described, in which participant observers at a university sports arena observed cases of aggressive behavior among the spectators. Based upon the literature review and the findings of the study, four…

  1. War, plague and exploitation in DR Congo

    Directory of Open Access Journals (Sweden)

    Dimčevska Antoaneta K.

    2007-01-01

    Full Text Available Late in autumn 2006 one of the headlines in world media was the first democratic elections in DR Congo. They took place after 30 years of Mobutu Sese Seko’s dictatorship and bloody civil wars in the period 1996-2002. These conflicts, which took approximately 4 million human lives, are called "The First African World War". Elections were held but they did not guarantee the end of trouble for the divided and tormented people in the northeast of Congo, the real scene of bloodshed. The area is still turbulent because it abounds in mineral wealth - gold, diamonds and raw materials for nuclear technology. For a whole decade, unscrupulous actors of the African crisis were fighting there, for illegal profits (achievable in the chaos of bloodshed rather than for democracy, defense of tribal interests, security, etc. as they claimed. In the mines of Eastern Congo unprecedented exploitation of people is still going on, especially of children, victims of conflicts, who suffer in great numbers from violence, starvation and diseases. These slaves of the crisis make local "warlords" and their mentors rich. The looting of the mines has stabilized the crisis because it makes possible enormous accumulation of wealth among armed decision-makers - which also includes availability of countless slaves-miners who have lost everything except their bare lives. Eastern Congo is, however, one of world’s three old focuses of plague; wild exploitation of ores in the area of this endemic disease has activated a sleepy focus and added pneumonic plague to the burdens suffered by the population of the rich but ill-fated region. This was to be expected because endemic plague in the gold-bearing evil circumstances impedes safe mining - and this will be the crucial challenge in the future of Congo. This article is an anthropological outline of the area where gold, plague, weapons and incomparable suffering of people merge together just because of cynic greed producing abuse

  2. WHO ARE FANS OF FACEBOOK FAN PAGES? AN ELECTRONIC WORD-OF-MOUTH COMMUNICATION PERSPECTIVE

    Directory of Open Access Journals (Sweden)

    Xiao Hu

    2014-12-01

    Full Text Available Given its great business value and popularity, Facebook fan pages have attracted more and more attention in both industry and academia. Fans of Facebook fan pages play an important role in electronic word-of-mouth (eWOM communication. This study focused on the population of fans on Facebook fan pages and examined the differences between fans and non-fans in terms of demographics, social network sites (SNS use, Internet use, and online shopping behaviors. The results indicated that fans used SNS more frequently than non-fans. Additionally, from the eWOM perspective, the researchers moderated product types in the model of people’s word-of-mouth (WOM preferences and found that people had different preferences for eWOM and traditional WOM for different products. Traditional WOM is still the most important source of information for people when shopping online.

  3. Football – Feminisation – Fans

    DEFF Research Database (Denmark)

    Mintert, Svenja-Maria

    Football has long time been considered as a genuine masculine domain. However, in the current football culture, the dualism of masculinity and femaleness is in progress. More and more women consume football which is in many countries considered the most popular sport, not only in Scandinavia where...... the number of female fans in football has grown over the past years. A national sense of community, emotion and passion for the game is in particular reached during the international tournaments at live football spectacles and many female fans cheer and sing for ‘their’ team with the utmost conviction. Yet......, the combination ‘women and football’ is still adhered to certain scepticism. Objective The overall objective of this Ph.D. thesis is to contribute to the body of knowledge associated with the distinct aspects of women’s football, female fandom and gender identities in European football drawing upon various...

  4. Will Passive Protection Save Congo Forests?

    Directory of Open Access Journals (Sweden)

    Gillian L Galford

    Full Text Available Central Africa's tropical forests are among the world's largest carbon reserves. Historically, they have experienced low rates of deforestation. Pressures to clear land are increasing due to development of infrastructure and livelihoods, foreign investment in agriculture, and shifting land use management, particularly in the Democratic Republic of Congo (DRC. The DRC contains the greatest area of intact African forests. These store approximately 22 billion tons of carbon in aboveground live biomass, yet only 10% are protected. Can the status quo of passive protection - forest management that is low or nonexistent - ensure the preservation of this forest and its carbon? We have developed the SimCongo model to simulate changes in land cover and land use based on theorized policy scenarios from 2010 to 2050. Three scenarios were examined: the first (Historical Trends assumes passive forest protection; the next (Conservation posits active protection of forests and activation of the national REDD+ action plan, and the last (Agricultural Development assumes increased agricultural activities in forested land with concomitant increased deforestation. SimCongo is a cellular automata model based on Bayesian statistical methods tailored for the DRC, built with the Dinamica-EGO platform. The model is parameterized and validated with deforestation observations from the past and runs the scenarios from 2010 through 2050 with a yearly time step. We estimate the Historical Trends trajectory will result in average emissions of 139 million t CO2 year-1 by the 2040s, a 15% increase over current emissions. The Conservation scenario would result in 58% less clearing than Historical Trends and would conserve carbon-dense forest and woodland savanna areas. The Agricultural Development scenario leads to emissions of 212 million t CO2 year-1 by the 2040s. These scenarios are heuristic examples of policy's influence on forest conservation and carbon storage. Our results

  5. Will Passive Protection Save Congo Forests?

    Science.gov (United States)

    Galford, Gillian L; Soares-Filho, Britaldo S; Sonter, Laura J; Laporte, Nadine

    2015-01-01

    Central Africa's tropical forests are among the world's largest carbon reserves. Historically, they have experienced low rates of deforestation. Pressures to clear land are increasing due to development of infrastructure and livelihoods, foreign investment in agriculture, and shifting land use management, particularly in the Democratic Republic of Congo (DRC). The DRC contains the greatest area of intact African forests. These store approximately 22 billion tons of carbon in aboveground live biomass, yet only 10% are protected. Can the status quo of passive protection - forest management that is low or nonexistent - ensure the preservation of this forest and its carbon? We have developed the SimCongo model to simulate changes in land cover and land use based on theorized policy scenarios from 2010 to 2050. Three scenarios were examined: the first (Historical Trends) assumes passive forest protection; the next (Conservation) posits active protection of forests and activation of the national REDD+ action plan, and the last (Agricultural Development) assumes increased agricultural activities in forested land with concomitant increased deforestation. SimCongo is a cellular automata model based on Bayesian statistical methods tailored for the DRC, built with the Dinamica-EGO platform. The model is parameterized and validated with deforestation observations from the past and runs the scenarios from 2010 through 2050 with a yearly time step. We estimate the Historical Trends trajectory will result in average emissions of 139 million t CO2 year-1 by the 2040s, a 15% increase over current emissions. The Conservation scenario would result in 58% less clearing than Historical Trends and would conserve carbon-dense forest and woodland savanna areas. The Agricultural Development scenario leads to emissions of 212 million t CO2 year-1 by the 2040s. These scenarios are heuristic examples of policy's influence on forest conservation and carbon storage. Our results suggest that 1

  6. Climatic and Tectonic Controls on Alluvial Fan Evolution: The Lost River Range, Idaho

    Science.gov (United States)

    Phillips, R. J.; Pierce, J. L.; Sharp, W. D.; Pierce, K. L.

    2006-12-01

    In the northern Basin &Range, alluvial fans developed along the Lost River range-front consist of several distinct inset fan segments with concave-up radial profiles. Multiple large radius (>5 km), shallow (2- 3°), alluvial fans extend across and beyond the active, ~140-km-long, normal Lost River fault. These large fans are relict features, formed by major sheetfloods that occurred intermittently between ~15-180 ka. More recent deposition has been dominated by debris-flows that form small-radius (cuts through gravelly fan deposits, indicates that the fan soils are geochemically suitable for uranium-series dating (median U=7ppm, 232Th=0.09ppm, 232Th/230Th=154). 230Th/U analysis of these calcic soils can thus provide precise temporal constraints on intervals of surface stability and subsequent soil formation. The oldest fan surface (Qfo1, 178+/-8 ka), exposed within the footwall of the trench, suggests an interval of surface stability, indicating that the fan was likely abandoned due to incision early in MIS 6. Incision may have resulted from surface faulting along the Arco segment of the Lost River fault, but could relate to changes in stream power or sediment supply associated with climatic change or with auto-cyclic variations within the drainage basin. A younger incised and faulted fan surface (Qfo2, 69+/-6 ka), likely represents active alluviation at the beginning of MIS 4 and, since it formed as hanging-wall alluvial gravel, provides age limits on an episode of fault displacement between Qfo1 and Qfo2. In situ pedogenic carbonate coats on sub-angular gravels within the colluvial fault wedge date at 68+/-2 ka, suggesting that either faulting occurred soon after Qfo2 stabilized or that soil carbonate coats were recycled into the colluvial wedge from the faulted surface. Further studies in the Lost River Range will assess the timing of fan deposition, surface stabilization and fault activity since the late Pleistocene using coupled application of Optically

  7. Acoustic Power Transmission Through a Ducted Fan

    Science.gov (United States)

    Envia, Ed

    2016-01-01

    For high-speed ducted fans, when the rotor flowfield is shock-free, the main contribution to the inlet radiated acoustic power comes from the portion of the rotor stator interaction sound field that is transmitted upstream through the rotor. As such, inclusion of the acoustic transmission is an essential ingredient in the prediction of the fan inlet noise when the fan tip relative speed is subsonic. This paper describes a linearized Euler based approach to computing the acoustic transmission of fan tones through the rotor. The approach is embodied in a code called LINFLUX was applied to a candidate subsonic fan called the Advanced Ducted Propulsor (ADP). The results from this study suggest that it is possible to make such prediction with sufficient fidelity to provide an indication of the acoustic transmission trends with the fan tip speed.

  8. Phylogeography of Crimean Congo Hemorrhagic Fever Virus

    Science.gov (United States)

    Klimentov, Alexander S.; Dzagurova, Tamara K.; Drexler, Jan Felix; Gmyl, Anatoly P.

    2016-01-01

    Crimean Congo hemorrhagic fever virus (CCHFV) is one of the most severe viral zoonozes. It is prevalent throughout Africa, Asia and southern Europe. Limited availability of sequence data has hindered phylogeographic studies. The complete genomic sequence of all three segments of 14 Crimean Congo hemorrhagic fever virus strains isolated from 1958–2000 in Russia, Central Asia and Africa was identified. Each genomic segment was independently subjected to continuous Bayesian phylogeographic analysis. The origin of each genomic segment was traced to Africa about 1,000–5,000 years ago. The virus was first introduced to South and Central Asia in the Middle Ages, and then spread to China, India and Russia. Reverse transfers of genomic segments from Asia to Africa were also observed. The European CCHFV genotype V was introduced to Europe via the Astrakhan region in South Russia 280–400 years ago and subsequently gradually spread westward in Russia, to Turkey and the Balkans less than 150 years ago. Only a few recombination events could be suggested in S and L genomic segments, while segment reassortment was very common. The median height of a non-reassortant phylogenetic tree node was 68–156 years. There were reassortment events within the European CCHFV lineage, but not with viruses from other locations. Therefore, CCHFV in Europe is a recently emerged zoonosis that represents a spillover from the global gene pool. PMID:27880794

  9. Forest elephant crisis in the Congo Basin.

    Science.gov (United States)

    Blake, Stephen; Strindberg, Samantha; Boudjan, Patrick; Makombo, Calixte; Bila-Isia, Inogwabini; Ilambu, Omari; Grossmann, Falk; Bene-Bene, Lambert; de Semboli, Bruno; Mbenzo, Valentin; S'hwa, Dino; Bayogo, Rosine; Williamson, Liz; Fay, Mike; Hart, John; Maisels, Fiona

    2007-04-01

    Debate over repealing the ivory trade ban dominates conferences of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). Resolving this controversy requires accurate estimates of elephant population trends and rates of illegal killing. Most African savannah elephant populations are well known; however, the status of forest elephants, perhaps a distinct species, in the vast Congo Basin is unclear. We assessed population status and incidence of poaching from line-transect and reconnaissance surveys conducted on foot in sites throughout the Congo Basin. Results indicate that the abundance and range of forest elephants are threatened from poaching that is most intense close to roads. The probability of elephant presence increased with distance to roads, whereas that of human signs declined. At all distances from roads, the probability of elephant occurrence was always higher inside, compared to outside, protected areas, whereas that of humans was always lower. Inside protected areas, forest elephant density was correlated with the size of remote forest core, but not with size of protected area. Forest elephants must be prioritised in elephant management planning at the continental scale.

  10. Forest elephant crisis in the Congo Basin.

    Directory of Open Access Journals (Sweden)

    Stephen Blake

    2007-04-01

    Full Text Available Debate over repealing the ivory trade ban dominates conferences of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES. Resolving this controversy requires accurate estimates of elephant population trends and rates of illegal killing. Most African savannah elephant populations are well known; however, the status of forest elephants, perhaps a distinct species, in the vast Congo Basin is unclear. We assessed population status and incidence of poaching from line-transect and reconnaissance surveys conducted on foot in sites throughout the Congo Basin. Results indicate that the abundance and range of forest elephants are threatened from poaching that is most intense close to roads. The probability of elephant presence increased with distance to roads, whereas that of human signs declined. At all distances from roads, the probability of elephant occurrence was always higher inside, compared to outside, protected areas, whereas that of humans was always lower. Inside protected areas, forest elephant density was correlated with the size of remote forest core, but not with size of protected area. Forest elephants must be prioritised in elephant management planning at the continental scale.

  11. Computing Gröbner fans

    DEFF Research Database (Denmark)

    Fukuda, K.; Jensen, Anders Nedergaard; Thomas, R.R.

    2005-01-01

    This paper presents algorithms for computing the Gröbner fan of an arbitrary polynomial ideal. The computation involves enumeration of all reduced Gröbner bases of the ideal. Our algorithms are based on a uniform definition of the Gröbner fan that applies to both homogeneous and non...... are not always normal fans of polyhedra in which case reverse search applies automatically. Computational results using our implementation of these algorithms in the software package Gfan are included....

  12. REFINEMENTS OF THE FAN-TODD'S INEQUALITIES

    Institute of Scientific and Technical Information of China (English)

    庄国基

    2002-01-01

    Refinements to inequalities oninner product spaces are presented. In this respect, inequalities dealt with in this paper are: Cauchy's inequality, Bessel's inequality, Fan-Todd's inequality and Fan-Todd's determinantal inequality. In each case, a strictly increasing function is put forward, which lies between the smaller and the larger quantities of each inequality. As a result,an improved condition for equality of the Fan-Todd's determinantal inequality is deduced.

  13. The Challenges of Teaching Fan Studies

    DEFF Research Database (Denmark)

    Stephan, Matthias

    , has only gained in popularity. Yet, the nature of the course in question, an interdisciplinary open elective, has meant a class with a variety of backgrounds, preparation, and expectations from fan studies and its critical apparatus. In addition, due to the course being taught in English, it attracts...... a conversation about the best methods for teaching fan studies, and help to open up fan studies to be integrated into other courses and programs....

  14. CPAFFC Delegation Visits Gabon, Republic of the Congo and Democratic Republic of the Congo

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>At the invitation of the Gabon-China Friendship Association (GCFA), the Congolese Association of Friendship Among the Peoples (CAFP) and the Mzee Laurent Desire Kabila Foundation of the Democratic Republic of the Congo, CPAFFC Vice President Feng Zuoku led a friendship delegation to visit the above three countries from September 20 to October 2, 2007. The delegation met with Prime Minister Jean Eye-ghe Ndong, Senate President Rene Radembino

  15. Active Control of Fan Noise

    Institute of Scientific and Technical Information of China (English)

    Nobuhiko YAMASAKI; Hirotoshi TAJIMA

    2008-01-01

    In the wake-rotor interaction fan noise, a number of the interacting modes at the blade passing frequency (BPF)and its harmonics are generated which are prescribed by the number of stator and rotor blades etc. In the present study, the dominant mode is tried to be suppressed by the secondary sound from the loudspeaker actuators. One of the novel features of the present system is the adoption of the control board with the Field Programmable Gate Array (FPGA) hardware and the LabVIEW software to synchronize the circumferentially installed loudspeaker actuators with the relative location of rotational blades under arbitrary fan rotational speeds. The experiments were conducted under the conditions of three rotational speeds of 2004, 3150, and 4002 [rpm]. The reduction in the sound pressure level (SPL) was observed for all three rotational speeds. The sound pressure level at the BPF was reduced approximately 13 [dB] for 2004 [rpm] case, but not so large reduction was attained for other cases probably due to the inefficiency of the loudspeaker actuators at high frequencies

  16. Physiological and biochemical responses of Chlorella vulgaris to Congo red.

    Science.gov (United States)

    Hernández-Zamora, Miriam; Perales-Vela, Hugo Virgilio; Flores-Ortíz, César Mateo; Cañizares-Villanueva, Rosa Olivia

    2014-10-01

    Extensive use of synthetic dyes in many industrial applications releases large volumes of wastewater. Wastewaters from dying industries are considered hazardous and require careful treatment prior to discharge into receiving water bodies. Dyes can affect photosynthetic activities of aquatic flora and decrease dissolved oxygen in water. The aim of this study was to evaluate the effect of Congo red on growth and metabolic activity of Chlorella vulgaris after 96h exposure. Exposure of the microalga to Congo red reduced growth rate, photosynthesis and respiration. Analysis of chlorophyll a fluorescence emission showed that the donor side of photosystem II was affected at high concentrations of Congo red. The quantum yield for electron transport (φEo), the electron transport rate (ETR) and the performance index (PI) also decreased. The reduction in the ability to absorb and use the quantum energy increased non-photochemical (NPQ) mechanisms for thermal dissipation. Overall, Congo red affects growth and metabolic activity in photosynthetic organisms in aquatic environments.

  17. DRAGON ROUGE: The Rescue of Hostages in the Congo

    Science.gov (United States)

    1980-01-01

    to traditionalism in a rural Africian society was usually also accompanied by manifestations of witchcraft , magic, and sorcery to explain misfortune... Witchcraft , Sorcery, Magic, and other Psychological Phenomena and their Implications on Military and Paramilitary Operations in the Congo. Washington

  18. Disarming war, arming peace: The Congo crisis, Dag ...

    African Journals Online (AJOL)

    leadership in the first Congo war, and apply in current attempts towards the .... repressive African regimes of the financial and military wherewithal to crack ..... strictly required to present their weapons in order to be granted access to the.

  19. Radar facies and architecture of alluvial fans and related sediments in high-energy alpine environments, British Columbia

    Science.gov (United States)

    Ekes, Csaba

    2000-08-01

    other environments, including those from gravel-bed rivers. None of the radar patterns observed in river channel environments were found on any of the alluvial fans surveyed. The objective of the second part of the thesis is the analysis of the large-scale, three dimensional internal architecture and depositional history of Cheekye Fan in southwestern British Columbia. The fan receives sediments from debris flows which represent a hazard for transportation and residential development on its surface. GPR proved to be an efficient technique for analysing the large-scale internal architecture of Cheekye Fan. Fan sediments overlie till and undulating bedrock in the northern and eastern fan sector. Two architectural components were defined: subaqueously-deposited fan-delta sediments and subaerial alluvial-fan sediments. Fan sediments were tentatively further divided into: (a) matrix-rich diamicton that appears predominant at the core of the fan and at lower stratigraphic horizons, suggesting bouldery rock-slide or debris flow origin, and (b) horizontally-bedded sheetflood sand and gravel dominating the upper 20--25 m of the stratigraphic column. Based on GPR data, radiocarbon dating and test-pit information, the post-glacial depositional history and evolution of Cheekye Fan is as follows. It is estimated that 90% of fan volume was deposited prior to 6000 years BP. Sediment availability declined after ca. 6000 yr. BP and fan growth slowed towards equilibrium. Although the last major debris flow which reached lower Cheekye Fan surface occurred at about 1300 yr. BP, Cheekye Fan is essentially a paraglacial fan, largely a product of the geological past. This fact should be taken into consideration when making future hazard estimates. Based on subsurface information there is little similarity between the early and late Holocene rates of deposition.

  20. Mycoremediation of Congo red dye by filamentous fungi

    Directory of Open Access Journals (Sweden)

    Sourav Bhattacharya

    2011-12-01

    Full Text Available Azo, anthroquinone and triphenylmethane dyes are the major classes of synthetic colourants, which are difficult to degrade and have received considerable attention. Congo red, a diazo dye, is considered as a xenobiotic compound, and is recalcitrant to biodegradative processes. Nevertheless, during the last few years it has been demonstrated that several fungi, under certain environmental conditions, are able to transfer azo dyes to non toxic products using laccases. The aim of this work was to study the factors influencing mycoremediation of Congo red. Several basidiomycetes and deuteromycetes species were tested for the decolourisation of Congo red (0.05 g/l in a semi synthetic broth at static and shaking conditions. Poor decolourisation was observed when the dye acted as the sole source of nitrogen, whereas semi synthetic broth supplemented with fertilizer resulted in better decolourisation. Decolourisation of Congo red was checked in the presence of salts of heavy metals such as mercuric chloride, lead acetate and zinc sulphate. Decolourisation parameters such as temperature, pH, and rpm were optimized and the decolourisation obtained at optimized conditions varied between 29.25- 97.28% at static condition and 82.1- 100% at shaking condition. Sodium dodecyl sulphate polyacrylamide gel electrophoretic analysis revealed bands with molecular weights ranging between 66.5 to 71 kDa, a characteristic of the fungal laccases. High efficiency decolourisation of Congo red makes these fungal forms a promising choice in biological treatment of waste water containing Congo red.

  1. Highly Loaded Fan by Using Tandem Cascade Rotor Blade

    Science.gov (United States)

    Hasegawa, Hiroaki; Suga, Shinya; Matsuoka, Akinori

    For axial flow compressors and fans in the aircraft engines higher pressure ratio is required in order to attain the high thrust engines. In this study, the fan with the tandem cascades was introduced to increase the fan pressure ratio. The use of tandem cascades in the fan allows savings in length and weight and therefore a compact fan could be built. The design of fan with tandem cascades and the fan testing were carried out to develop the high pressure ratio fan for the Air Turbo Ramjet (ATR) propulsion system. The ATR is a combined cycle engine which performs like a turbojet engine at subsonic speeds and a ramjet at supersonic speeds. In particular, high fan pressure ratio contributes to increase the engine thrust during subsonic flight at which the engine does not make use of ram effect. The results of the fan testing indicate that the pressure ratio of 2.2 is achieved in single stage fan.

  2. Turbofan gas turbine engine with variable fan outlet guide vanes

    Science.gov (United States)

    Wood, Peter John (Inventor); Zenon, Ruby Lasandra (Inventor); LaChapelle, Donald George (Inventor); Mielke, Mark Joseph (Inventor); Grant, Carl (Inventor)

    2010-01-01

    A turbofan gas turbine engine includes a forward fan section with a row of fan rotor blades, a core engine, and a fan bypass duct downstream of the forward fan section and radially outwardly of the core engine. The forward fan section has only a single stage of variable fan guide vanes which are variable fan outlet guide vanes downstream of the forward fan rotor blades. An exemplary embodiment of the engine includes an afterburner downstream of the fan bypass duct between the core engine and an exhaust nozzle. The variable fan outlet guide vanes are operable to pivot from a nominal OGV position at take-off to an open OGV position at a high flight Mach Number which may be in a range of between about 2.5-4+. Struts extend radially across a radially inwardly curved portion of a flowpath of the engine between the forward fan section and the core engine.

  3. Dynamic response of Hovercraft lift fans

    Science.gov (United States)

    Moran, D. D.

    1981-08-01

    Hovercraft lift fans are subjected to varying back pressure due to wave action and craft motions when these vehicles are operating in a seaway. The oscillatory back pressure causes the fans to perform dynamically, exhibiting a hysteresis type of response and a corresponding degradation in mean performance. Since Hovercraft motions are influenced by variations in lift fan pressure and discharge, it is important to understand completely the nature of the dynamic performance of lift fans in order to completely solve the Hovercraft seakeeping problem. The present study was performed to determine and classify the instabilities encountered in a centrifugal fan operating against time-varying back pressure. A model-scale experiment was developed in which the fan discharge was directed into a flow-measuring device, terminating in a rotating valve which produced an oscillatory back pressure superimposed upon a mean aerodynamic resistance. Pressure and local velocity were measured as functions of time at several locations in the fan volute. The measurements permitted the identification of rotating (or propagating) stall in the impeller. One cell and two cell configurations were classified and the transient condition connecting these two configurations was observed. The mechanisms which lead to rotating stall in a centrifugal compressor are presented and discussed with specific reference to Hovercraft applications.

  4. Fan-structure waves in shear ruptures

    Science.gov (United States)

    Tarasov, Boris

    2016-04-01

    This presentation introduces a recently identified shear rupture mechanism providing a paradoxical feature of hard rocks - the possibility of shear rupture propagation through the highly confined intact rock mass at shear stress levels significantly less than frictional strength. According to the fan-mechanism the shear rupture propagation is associated with consecutive creation of small slabs in the fracture tip which, due to rotation caused by shear displacement of the fracture interfaces, form a fan-structure representing the fracture head. The fan-head combines such unique features as: extremely low shear resistance (below the frictional strength), self-sustaining stress intensification in the rupture tip (providing easy formation of new slabs), and self-unbalancing conditions in the fan-head (making the failure process inevitably spontaneous and violent). An important feature of the fan-mechanism is the fact that for the initial formation of the fan-structure an enhanced local shear stress is required, however, after completion of the fan-structure it can propagate as a dynamic wave through intact rock mass at shear stresses below the frictional strength. Paradoxically low shear strength of pristine rocks provided by the fan-mechanism determines the correspondingly low transient strength of the lithosphere, which favours generation of new earthquake faults in the intact rock mass adjoining pre-existing faults in preference to frictional stick-slip instability along these faults. The new approach reveals an alternative role of pre-existing faults in earthquake activity: they represent local stress concentrates in pristine rock adjoining the fault where special conditions for the fan-mechanism nucleation are created, while further dynamic propagation of the new fault (earthquake) occurs at low field stresses even below the frictional strength.

  5. A structurally controlled fan-delta complex at the southern margin of the peninsular range forearc basin complex (Baja California)

    Energy Technology Data Exchange (ETDEWEB)

    Morris, W.R.; Busby-Spera, C. (Univ. of California, Santa Barbara (USA))

    1990-05-01

    A confined trunk fan delta and its structurally controlled tributary fan deltas are extremely well exposed along the southern margin of the Rosario embayment. This fan-delta complex consists of nonmarine to deep marine deposits almost continuously exposed for over 20 km in the down-paleoslope direction. Facies and stratal patterns in the fan-delta complex were controlled by local faulting, climatic variation, and eustasy, resulting in relative sea level fluctuations. Basin bathymetry and drainage patterns were controlled by a series of half-grabens that formed along north-south-trending faults that lay along the northern margin of an east-west-trending depression. Breccias were initially shed into the north-south-trending half-grabens; axial drainage systems were later established within the grabens, making up the tributary fan deltas. These tributary fan deltas fed a voluminous trunk fan delta confined to the east-west-trending depression. The trunk and tributary fan delta deposits show two major progradational to retrogradational cycles that record relative sea level fluctuations. Progradation in the shallow-marine environment is represented by conglomerate channels cut into ripple-laminated or bioturbated siltstone and HCS sandstones, overlain by conglomerate mouth bar deposits interstratified with nearshore sandstone deposits. Retrogradation in the shallow marine environment is recorded by either a vertical clastic facies transition or a clastic-carbonate facies transition. The clastic facies transition consists of nearshore sandstone deposits overlain by offshore bioturbated siltstones. The clastic-carbonate facies transition consists of the development of red algal patch reefs and rhodoliths on top of fan-delta conglomeratic lobes, mudstone and sandstone bank channel margins, or paleobasement highs. The clastic-carbonate facies transition reflects low sediment supply controlled by climatic conditions.

  6. Disabled Woman Heads Beijing Fans Association

    Institute of Scientific and Technical Information of China (English)

    1995-01-01

    THE next time you go to a football match in Beijing, look around the edge of the field. You might see a young woman in a wheelchair cheering her favorite team. Wu Jinghong is more than a handicapped person, more than a woman football fan. She is the head of the Beijing Football Fans Association, a group more than 1,000 members strong. Wu alone started the association in 1988 and because she is a woman, encouraged other women fans to openly support their favorite teams.

  7. Sherlock (Holmes in Japanese (fan works [symposium

    Directory of Open Access Journals (Sweden)

    Lori Morimoto

    2017-03-01

    Full Text Available I explore the history of Japanese writing centered on Sherlock Holmes as a means of interrogating the 2014 BBC Sherlock pastiche John and Sherlock Casebook 1: Jon, zenchi renmei e iku (The stark naked league, written by Japanese Sherlockian Kitahara Naohiko for mainstream publication by the publishing house Hayakawa shobō. I argue that exploration of the Japanese (fan cultural contexts of Kitahara's book begins to reveal the limits of the Anglo-American-centered framework through which fan studies scholars explore fan/producer relationships.

  8. Lightning climatology in the Congo Basin

    Science.gov (United States)

    Soula, S.; Kasereka, J. Kigotsi; Georgis, J. F.; Barthe, C.

    2016-09-01

    The lightning climatology of the Congo Basin including several countries of Central Africa is analysed in detail for the first time. It is based on data from the World Wide Lightning Location Network (WWLLN), for the period from 2005 to 2013. A comparison of these data with Lightning Imaging Sensor (LIS) data for the same period shows the relative detection efficiency of the WWLLN (DE) in the 2500 km × 2500 km region increases from about 1.70% in the beginning of the period to 5.90% in 2013, and it is in agreement with previous results for other regions of the world. However, the increase of DE is not uniform over the whole region. The average monthly flash rate describes an annual cycle with a strong activity from October to March and a low one from June to August, associated with the ITCZ migration but not exactly symmetrical on both sides of the equator. The zonal distribution of the lightning flashes exhibits a maximum between 1°S and 2°S and about 56% of the flashes are located south of the equator in the 10°S-10°N interval. The diurnal evolution of the flash rate has a maximum between 1400 and 1700 UTC, according to the reference year. The annual flash density and number of stormy days show a sharp maximum localized in the eastern part of Democratic Republic of Congo (DRC) regardless of the reference year and the period of the year. These maxima reach 12.86 fl km- 2 and 189 days, respectively, in 2013, and correspond to a very active region located at the rear of the Virunga mountain range at altitudes that exceed 3000 m. The presence of these mountains plays a role in the thunderstorm development along the year. The estimation of this local maximum of the lightning density by taking into account the DE, leads to a value consistent with that of the global climatology by Christian et al. (2003).

  9. 30 CFR 75.311 - Main mine fan operation.

    Science.gov (United States)

    2010-07-01

    ... back-up fan system— (1) Only persons necessary to evaluate the effect of the fan stoppage or restart... back-up fan system is used that does not provide the ventilating quantity provided by the main mine fan... fire or other products of combustion are approved in the ventilation plan. (g) If multiple mine...

  10. PICNIC - FANS, ULTRAS AND HOOLIGANS - INTERNAL DIFFERENTIATE OF SUBCULTURE GROUP FOOTBALL FANS IN POLAND

    Directory of Open Access Journals (Sweden)

    Maciej Solinski

    2006-01-01

    Full Text Available This article is a main part of "Internal differentiate of subculture group of football fans in Poland" project. Author has tried to show how the subculture of football fans can be differentiate. Author ha presented three different subgroups of Polish fans. It is very important to divide this subculture, because each subgroup has different mentality and style. That is why I have paid the most attention on this element.

  11. Knowing fans, knowing music : an exploration of fan interaction on Twitter

    OpenAIRE

    2011-01-01

    In this thesis, I examine what "knowing music" means to participants in online social musicking activities, along with the role Twitter plays in this process. I compare the way I came to "know" music through social networks with others' behaviors regarding music and social networking. Using Henry Jenkins's research framework as an aca-fan (a portmanteau word combining academic and fan), I study fan communities from the inside out. I begin by outlining my story of coming to know the music that...

  12. Numerical Analysis for the Air Flow of Cross Flow Fan

    Science.gov (United States)

    Sakai, Hirokazu; Tokushge, Satoshi; Ishikawa, Masatoshi; Ishihara, Takuya

    There are many factors for designing the cross flow fan. Therefore, the performance of cross flow fan is not clear yet. We can analyze the transient flow of a cross flow fan using sliding mesh approach. One of the tasks using Computational Fluid Dynamics (CFD) is a way of modeling for analysis heat exchangers with cross flow fan. These tasks are very important for design. The paper has a modeling of heat exchangers and meshing the fan blades. The next tasks, we focus the ability of cross flow fan when we change the geometry of fan blades.

  13. Active Vibration Reduction of Titanium Alloy Fan Blades (FAN1) Using Piezoelectric Materials

    Science.gov (United States)

    Choi, Benjamin; Kauffman, Jeffrey; Duffy, Kirsten; Provenza, Andrew; Morrison, Carlos

    2010-01-01

    The NASA Glenn Research Center is developing smart adaptive structures to improve fan blade damping at resonances using piezoelectric (PE) transducers. In this paper, a digital resonant control technique emulating passive shunt circuits is used to demonstrate vibration reduction of FAN1 Ti real fan blade at the several target modes. Single-mode control and multi-mode control using one piezoelectric material are demonstrated. Also a conceptual study of how to implement this digital control system into the rotating fan blade is discussed.

  14. How to do things with fan subs: Media engagement as subcultural capital in anime fan subbing

    Directory of Open Access Journals (Sweden)

    Douglas Schules

    2014-09-01

    Full Text Available Anime fandom has been a fairly constant subject in fan scholarship, although only recently have conversations about fan subbing begun to circulate. As useful as those conversations are, none have directly dealt either with the mechanisms of fan subbing, particularly the use of linear notes, as a practice or with how these subs intersect with the flows of subcultural capital. Fan subbing, both as a productive and a consumptive practice, plays a small but influential part in subcultural capital. Engagement with media is a compositional element of such capital in this community.

  15. Magnetic anomalies in Central Bengal fan

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, T.C.S.; Lakshminarayana, S.; Sarma, K.V.L.N.S.

    Total magnetic field anomalies recorded over the Central Bengal Fan are analysed and the depths to the magnetic basement are computed using the analytical signal and the Werner deconvolution methods. To the west and east of 85 degrees E...

  16. Computing Gröbner fans

    DEFF Research Database (Denmark)

    Fukuda, K.; Jensen, Anders Nedergaard; Thomas, R.R.

    2005-01-01

    This paper presents algorithms for computing the Gröbner fan of an arbitrary polynomial ideal. The computation involves enumeration of all reduced Gröbner bases of the ideal. Our algorithms are based on a uniform definition of the Gröbner fan that applies to both homogeneous and non......-homogeneous ideals and a proof that this object is a polyhedral complex. We show that the cells of a Gröbner fan can easily be oriented acyclically and with a unique sink, allowing their enumeration by the memory-less reverse search procedure. The significance of this follows from the fact that Gröbner fans...

  17. Quiet, High-Efficiency Vaneaxial Fans Project

    Data.gov (United States)

    National Aeronautics and Space Administration — During this Phase I effort, CRG proposes to demonstrate the ability to significantly reduce the acoustic signature of vaneaxial fans by establishing quiet...

  18. Mexican Fan Palm - Orange Co. [ds350

    Data.gov (United States)

    California Department of Resources — This dataset provides the known distribution of Mexican fan palm (Washingtonia robusta) in southern Orange County. The surveys were conducted from May to June, 2007...

  19. Synchronous and Cogged Fan Belt Performance Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Cutler, D.; Dean, J.; Acosta, J.

    2014-02-01

    The GSA Regional GPG Team commissioned the National Renewable Energy Laboratory (NREL) to perform monitoring of cogged V-belts and synchronous belts on both a constant volume and a variable air volume fan at the Byron G. Rodgers Federal Building and U.S. Courthouse in Denver, Colorado. These motor/fan combinations were tested with their original, standard V-belts (appropriately tensioned by an operation and maintenance professional) to obtain a baseline for standard operation. They were then switched to the cogged V-belts, and finally to synchronous belts. The power consumption by the motor was normalized for both fan speed and air density changes. This was necessary to ensure that the power readings were not influenced by a change in rotational fan speed or by the power required to push denser air. Finally, energy savings and operation and maintenance savings were compiled into an economic life-cycle cost analysis of the different belt options.

  20. Palo Monte, um rito Congo em Cuba

    Directory of Open Access Journals (Sweden)

    José da Silva Ribeiro

    2007-01-01

    Full Text Available Juntaram-se em Cuba a partir do século XVI africanos provenientes de toda a costa ocidental africana pertencentes a muitos grupos étnicos. Estes em contacto com as culturas em presença (autóctone, espanhola, portuguesa, africanas desenvolveram diversos sistemas de crença, rituais e práticas mágico-religiosas. No Século XIX o dia de Reis construía o momento mais alto da afirmação da cultura africana em Cuba. Estas manifestações eram acompanhadas da coroação de reis e rainhas Congo, figuras principais da festa e da vida social africana.Africans coming from all West Africa coasts from a large variety of ethnic groups gathered in Cuba since XVIth century. These, in contact with other cultures (native, Spanish, Portuguese, Africans developed some belief systems, rituals and magical-religious practices. On XIXth century the King’s day was the highest moment of affirmation of African culture in Cuba. These experiences were accompanied of king and queen’s crowning, principal figures of African festival and social life.

  1. Crimean-Congo hemorrhagic fever in Iran

    Science.gov (United States)

    Keshtkar-Jahromi, Maryam; Sajadi, Mohammad M.; Ansari, Hossein; Mardani, Masoud; Naieni, Kourosh Holakouie

    2014-01-01

    The presence of Crimean-Congo hemorrhagic fever virus (CCHFV) in Iran was first identified in studies of livestock sera and ticks in the 1970s, but the first human infection was not diagnosed until 1999. Since that time, the number of cases of CCHF in Iran has markedly increased. Through January 2012, articles in the published literature have reported a total of 870 confirmed cases, with 126 deaths, for a case fatality rate (CFR) of 17.6%. The disease has been seen in 26 of the country’s 31 provinces, with the greatest number of cases in Sistan and Baluchestan, Isfahan, Fars, Tehran, Khorasan, and Khuzestan provinces. The increase in CCHF in Iran has paralleled that in neighboring Turkey, though the number of cases in Turkey has been much larger, with an overall CFR of around 5%. In this article, we review the features of CCHF in Iran, including its history, epidemiology, animal and tick reservoirs, current surveillance and control programs, diagnostic methods, clinical features and experience with ribavirin therapy, and consider possible explanations for the difference in the CFR of CCHF between Iran and Turkey. The emergence of CCHF in Iran calls for countermeasures at many levels to protect the population, but also provides opportunities for studying the epidemiology, diagnosis and management of the disease. PMID:23872313

  2. Crimean-Congo Hemorrhagic Fever: An Overview

    Institute of Scientific and Technical Information of China (English)

    Serkan (O)ncü

    2013-01-01

    Crimean-Congo hemorrhagic fever (CCHF) is a zoonotic viral infection that is a serious threat to humans.The disease is widely distributed in Africa,Asia,and Europe and has developed into a serious public health concern.Humans become infected through the bites of ticks,by contact with a patient with CCHF,or by contact with blood or tissues from viremic livestock.Microvascular instability and impaired hemostasis are the hallmarks of the infection.Infection in human begins with nonspecific febrile symptoms,but may progress to a serious hemorrhagic syndrome with high mortality rates.Enzyme-linked immunoassay (ELISA) and polymerase chain reaction (PCR) are the most used and specific tests for the diagnosis.The mainstay of treatment is supportive.Although definitive studies are not available,ribavirin is suggested to be effective especially at the earlier phase of the infection.Uses of universal protective measures are the best way to avoid the infection.In this review,all aspects of CCHF are overviewed in light of the current literature.

  3. Crimean-Congo hemorrhagic fever in Iran.

    Science.gov (United States)

    Keshtkar-Jahromi, Maryam; Sajadi, Mohammad M; Ansari, Hossein; Mardani, Masoud; Holakouie-Naieni, Kourosh

    2013-10-01

    The presence of Crimean-Congo hemorrhagic fever virus (CCHFV) in Iran was first identified in studies of livestock sera and ticks in the 1970s, but the first human infection was not diagnosed until 1999. Since that time, the number of cases of CCHF in Iran has markedly increased. Through January 2012, articles in the published literature have reported a total of 870 confirmed cases, with 126 deaths, for a case fatality rate (CFR) of 17.6%. The disease has been seen in 26 of the country's 31 provinces, with the greatest number of cases in Sistan and Baluchestan, Isfahan, Fars, Tehran, Khorasan, and Khuzestan provinces. The increase in CCHF in Iran has paralleled that in neighboring Turkey, though the number of cases in Turkey has been much larger, with an overall CFR of around 5%. In this article, we review the features of CCHF in Iran, including its history, epidemiology, animal and tick reservoirs, current surveillance and control programs, diagnostic methods, clinical features and experience with ribavirin therapy, and consider possible explanations for the difference in the CFR of CCHF between Iran and Turkey. The emergence of CCHF in Iran calls for countermeasures at many levels to protect the population, but also provides opportunities for studying the epidemiology, diagnosis and management of the disease.

  4. Wordplay, mindplay: Fan fiction and postclassical narratology

    Directory of Open Access Journals (Sweden)

    Veerle Van Steenhuyse

    2014-09-01

    Full Text Available Recent narrative theories on story worlds, or the worlds evoked by narratives, call attention to the process of fan reading and the role which the canon plays in that process. This paper posits that such theories can help us understand literary techniques that make a difference on the level of the reading experience that is implied by fan fiction texts. This is illustrated with a close reading of Naguabo's "The Mother of All Marriage Proposals," a Jane Austen fic.

  5. Integral Compressor/Generator/Fan Unitary Structure

    OpenAIRE

    Dreiman, Nelik

    2016-01-01

    INTEGRAL COMPRESSOR / GENERATOR / FAN UNITARY STRUCTURE.*) Dr. Nelik Dreiman Consultant, P.O.Box 144, Tipton, MI E-mail: An extremely compact, therefore space saving single compressor/generator/cooling fan structure of short axial length and light weight has been developed to provide generation of electrical power with simultaneous operation of the compressor when power is unavailable or function as a regular AC compressor powered by a power line. The generators and ai...

  6. Fan affinity laws from a collision model

    CERN Document Server

    Bhattacharjee, Shayak

    2012-01-01

    The performance of a fan is usually estimated from hydrodynamical considerations. The calculations are long and involved and the results are expressed in terms of three affinity laws. In this work we use kinetic theory to attack this problem. A hard sphere collision model is used, and subsequently a correction to account for the flow behaviour of air is incorporated. Our calculations prove the affinity laws and provide numerical estimates of the air delivery, thrust and drag on a rotating fan.

  7. Aerodynamic modelling and optimization of axial fans

    Energy Technology Data Exchange (ETDEWEB)

    Noertoft Soerensen, Dan

    1998-01-01

    A numerically efficient mathematical model for the aerodynamics of low speed axial fans of the arbitrary vortex flow type has been developed. The model is based on a blade-element principle, whereby the rotor is divided into a number of annular stream tubes. For each of these stream tubes relations for velocity, pressure and radial position are derived from the conservation laws for mass, tangential momentum and energy. The equations are solved using the Newton-Raphson methods, and solutions converged to machine accuracy are found at small computing costs. The model has been validated against published measurements on various fan configurations, comprising two rotor-only fan stages, a counter-rotating fan unit and a stator-rotor stator stage. Comparisons of local and integrated properties show that the computed results agree well with the measurements. Optimizations have been performed to maximize the mean value of fan efficiency in a design interval of flow rates, thus designing a fan which operates well over a range of different flow conditions. The optimization scheme was used to investigate the dependence of maximum efficiency on 1: the number of blades, 2: the width of the design interval and 3: the hub radius. The degree of freedom in the choice of design variable and constraints, combined with the design interval concept, provides a valuable design-tool for axial fans. To further investigate the use of design optimization, a model for the vortex shedding noise from the trailing edge of the blades has been incorporated into the optimization scheme. The noise emission from the blades was minimized in a flow rate design point. Optimizations were performed to investigate the dependence of the noise on 1: the number of blades, 2: a constraint imposed on efficiency and 3: the hub radius. The investigations showed, that a significant reduction of noise could be achieved, at the expense of a small reduction in fan efficiency. (EG) 66 refs.

  8. Radiated noise of ducted fans

    Science.gov (United States)

    Eversman, Walter

    The differences in the radiated acoustic fields of ducted and unducted propellers of the same thrust operating under similar conditions are investigated. An FEM model is created for the generation, propagation, and radiation of steady, rotor alone noise and exit guide vane interaction noise of a ducted fan. For a specified number of blades, angular mode harmonic, and rotor angular velocity, the acoustic field is described in a cylindrical coordinate system reduced to only the axial and radial directions. It is found that, contrary to the usual understanding of the Tyler and Sofrin (1962) result, supersonic tip speed rotor noise can be cut off if the tip Mach number is only slightly in excess of unity and if the number of blades is relatively small. If there are many blades, the fundamental angular mode number is large, and the Tyler and Sofrin result for thin annuli becomes more relevant. Shrouding of subsonic tip speed propellers is a very effective means of controlling rotor alone noise.

  9. Controls on morphometry and morphology of alluvial and colluvial fans in the high-Arctic setting, Petuniabukta, Svalbard.

    Science.gov (United States)

    Tomczyk, Aleksandra; Ewertowski, Marek

    2016-04-01

    The Petuniabukta (78o42' N, 16o32') is a bay in the northern part of Billefjorden in the central part of Spitsbergen Island, Svalbard. The bay is surrounded by six major, partly glaciated valleys. A numerous alluvial and colluvial fans have developed within valleys as well as along the fiord margins. Distribution and characterization of morphometric parameters of fans were investigated using time-series of orthophotos and digital elevation models (generated based on 1961, 1990, 2009 aerial photographs) and high resolution satellite imagery from 2013. In addition, a very detailed DEM and orthophoto (5 cm resolution) have been produced from unmanned aerial vehicle (UAV) imagery from 2014 and 2015, covering three fans characterised by different types of surface morphology. A 1:40,000 map showing the distribution of almost 300 alluvial and colluvial fans (ranging in area from 325 km2 to 451 275 km2), together with time-series of 1:5,000 geomorphological maps of sample fans enabled an assessment of the spatial and temporal evolution of processes responsible for delivery and erosion of sediments from the fans. The relationship between terrain parameters (e.g. slope, exposition) as well as geology was also investigated. Many of the studied alluvial fans were at least partly coupled and sediments were transferred from the upstream zone to the downstream zone, either due to debris-flow or channelized stream flow. In other cases, coarse sediments were stored within fans, and fines were transported downstream by sheet flows or sub-surface flows. In most of smaller colluvial fans and debris cones, sediments were delivered by mass movement processes (mainly rockfalls and snowfalls) and did not reach lower margin of landforms. Analysis of historical aerial photographs indicated recent increase in the activity of debris-flow modification of surface morphology of fans. Fans located outside limits of the Little Ice Age (LIA) glaciation are dominated by the secondary processes

  10. Managing for timber and biodiversity in the Congo Basin

    DEFF Research Database (Denmark)

    Nasi, Robert; Billand, Alain; van Vliet, Nathalie

    2012-01-01

    Multiple-use forest management is considered by many as a preferable alternative to single-use, generally timber-dominant, management models. In the Congo Basin rainforests, integration of timber and non-timber forest resources plays a key role in the subsistence and market economies of rural...... communities. This is however mainly occurring in ‘‘ordinary’’ forest lands and not in formally gazetted forest lands. In this paper we briefly explore the major land-uses in the Congo Basin and their actual or potential for multiple-use. We then focus on the most extant production system (industrial logging...

  11. The Connemara Fan: a major glacial grounding line fan west of Ireland

    Science.gov (United States)

    McCarron, Stephen; Praeg, Daniel; Monteys, Xavier; Scott, Gill

    2014-05-01

    Glacigenic topography on the mid-shelf (~130-350 m water depth) west of Galway, Ireland appears to have the morphological form, internal architecture and sediments associated with a large glacial grounding-line fan. Seismic data collected in 2009 and 2012 (during the GLAMAR and GATEWAYS 1 campaigns) reveal that the broad, arcuate ridges of the 'Olex moraine' form the landward part of a fan system which prograded beyond the mid-shelf break (defining the outer margin of the 'Clare Platform') westwards into the Porcupine Seabight. The topography is comparable to larger shelf-edge trough-mouth fans found further north along the same margin, however no discernible 'trough' has been identified on the Clare Platform. The ridge and fan topographic assemblage is renamed the 'Connemara Fan' in its entirety, based on its genetic relations and geographic location due west of Connemara, western Ireland. A macrofossil recovered from within a debris flow on the outer fan slope comprised of remobilised plumites dates to ~ 20 ka Cal B.P., indicating sediment reworking downslope following deglacial sediment input to at least that time. The Connemara Fan is the most southerly glacigenic fan identified along the north-east Atlantic margin. Its identification also adds to our knowledge of possibly multiple generations of ice sheets feeding onto the Irish shelf from west-central Ireland and the occurrence of ice sheet geometries and dynamics that evacuated ice, melt-water and sediment (ice streams?) westwards across the Clare Platform during past glaciations.

  12. Fan relationship management in football - going beyond traditional product offerings to win the hearts of fans

    DEFF Research Database (Denmark)

    Cortsen, Kenneth

    2015-01-01

    The management and control of fan relations should go beyond a football club’s traditional product and service offerings and touch the important experiential side of the football economy. This will create a stronger platform to optimize ROI, ROE and ROO relating to different fan segments....

  13. Novel Crosstalk Measurement Method for Multi-Core Fiber Fan-In/Fan-Out Devices

    DEFF Research Database (Denmark)

    Ye, Feihong; Ono, Hirotaka; Abe, Yoshiteru;

    2016-01-01

    We propose a new crosstalk measurement method for multi-core fiber fan-in/fan-out devices utilizing the Fresnel reflection. Compared with the traditional method using core-to-core coupling between a multi-core fiber and a single-mode fiber, the proposed method has the advantages of high reliabili...

  14. Design Guidelines for Quiet Fans and Pumps for Space Vehicles

    Science.gov (United States)

    Lovell, John S.; Magliozzi, Bernard

    2008-01-01

    This document presents guidelines for the design of quiet fans and pumps of the class used on space vehicles. A simple procedure is presented for the prediction of fan noise over the meaningful frequency spectrum. A section also presents general design criteria for axial flow fans, squirrel cage fans, centrifugal fans, and centrifugal pumps. The basis for this report is an experimental program conducted by Hamilton Standard under NASA Contract NAS 9-12457. The derivations of the noise predicting methods used in this document are explained in Hamilton Standard Report SVHSER 6183, "Fan and Pump Noise Control," dated May 1973 (6).

  15. Numerical Aerodynamic Evaluation and Noise Investigation of a Bladeless Fan

    OpenAIRE

    mohammad jafari; Hossein Afshin; Bijan Farhanieh; Hamidreza bozorgasareh

    2015-01-01

    Bladeless fan is a novel fan type that has no observable impeller, usually used for domestic applications. Numerical investigation of a Bladeless fan via Finite Volume Method was carried out in this study. The fan was placed in center of a 4×2×2m room and 473 Eppler airfoil profile was used as cross section of the fan. Performance and noise level of the fan by solving continuity and momentum equations as well as noise equations of Broadband Noise Source (BNS) and Ffowcs Williams a...

  16. Climate Change Impacts on the Congo Basin Region

    NARCIS (Netherlands)

    Ludwig, F.; Franssen, W.; Jans, W.W.P.; Kruijt, B.; Supit, I.

    2012-01-01

    This report presents analyses of climate change impacts in the Congo Basin on water for agriculture and hydropower, forest ecosystem functioning and carbon storage and impacts of climate variability and change on future economic development. To quantify the impacts of future climate we developed a m

  17. Optimism Bias in Fans and Sports Reporters.

    Directory of Open Access Journals (Sweden)

    Bradley C Love

    Full Text Available People are optimistic about their prospects relative to others. However, existing studies can be difficult to interpret because outcomes are not zero-sum. For example, one person avoiding cancer does not necessitate that another person develops cancer. Ideally, optimism bias would be evaluated within a closed formal system to establish with certainty the extent of the bias and the associated environmental factors, such that optimism bias is demonstrated when a population is internally inconsistent. Accordingly, we asked NFL fans to predict how many games teams they liked and disliked would win in the 2015 season. Fans, like ESPN reporters assigned to cover a team, were overly optimistic about their team's prospects. The opposite pattern was found for teams that fans disliked. Optimism may flourish because year-to-year team results are marked by auto-correlation and regression to the group mean (i.e., good teams stay good, but bad teams improve.

  18. Optimism Bias in Fans and Sports Reporters.

    Science.gov (United States)

    Love, Bradley C; Kopeć, Łukasz; Guest, Olivia

    2015-01-01

    People are optimistic about their prospects relative to others. However, existing studies can be difficult to interpret because outcomes are not zero-sum. For example, one person avoiding cancer does not necessitate that another person develops cancer. Ideally, optimism bias would be evaluated within a closed formal system to establish with certainty the extent of the bias and the associated environmental factors, such that optimism bias is demonstrated when a population is internally inconsistent. Accordingly, we asked NFL fans to predict how many games teams they liked and disliked would win in the 2015 season. Fans, like ESPN reporters assigned to cover a team, were overly optimistic about their team's prospects. The opposite pattern was found for teams that fans disliked. Optimism may flourish because year-to-year team results are marked by auto-correlation and regression to the group mean (i.e., good teams stay good, but bad teams improve).

  19. ANALYTICAL METHODS FOR CALCULATING FAN AERODYNAMICS

    Directory of Open Access Journals (Sweden)

    Jan Dostal

    2015-12-01

    Full Text Available This paper presents results obtained between 2010 and 2014 in the field of fan aerodynamics at the Department of Composite Technology at the VZLÚ aerospace research and experimental institute in Prague – Letnany. The need for rapid and accurate methods for the preliminary design of blade machinery led to the creation of a mathematical model based on the basic laws of turbomachine aerodynamics. The mathematical model, the derivation of which is briefly described below, has been encoded in a computer programme, which enables the theoretical characteristics of a fan of the designed geometry to be determined rapidly. The validity of the mathematical model is assessed continuously by measuring model fans in the measuring unit, which was developed and manufactured specifically for this purpose. The paper also presents a comparison between measured characteristics and characteristics determined by the mathematical model as the basis for a discussion on possible causes of measured deviations and calculation deviations.

  20. Fan Noise Source Diagnostic Test: Rotor Alone Aerodynamic Performance Results

    Science.gov (United States)

    Hughes, Christopher E.; Jeracki, Robert J.; Woodward, Richard P.; Miller, Christopher J.

    2005-01-01

    The aerodynamic performance of an isolated fan or rotor alone model was measured in the NASA Glenn Research Center 9- by 15- Foot Low Speed Wind Tunnel as part of the Fan Broadband Source Diagnostic Test conducted at NASA Glenn. The Source Diagnostic Test was conducted to identify the noise sources within a wind tunnel scale model of a turbofan engine and quantify their contribution to the overall system noise level. The fan was part of a 1/5th scale model representation of the bypass stage of a current technology turbofan engine. For the rotor alone testing, the fan and nacelle, including the inlet, external cowl, and fixed area fan exit nozzle, were modeled in the test hardware; the internal outlet guide vanes located behind the fan were removed. Without the outlet guide vanes, the velocity at the nozzle exit changes significantly, thereby affecting the fan performance. As part of the investigation, variations in the fan nozzle area were tested in order to match as closely as possible the rotor alone performance with the fan performance obtained with the outlet guide vanes installed. The fan operating performance was determined using fixed pressure/temperature combination rakes and the corrected weight flow. The performance results indicate that a suitable nozzle exit was achieved to be able to closely match the rotor alone and fan/outlet guide vane configuration performance on the sea level operating line. A small shift in the slope of the sea level operating line was measured, which resulted in a slightly higher rotor alone fan pressure ratio at take-off conditions, matched fan performance at cutback conditions, and a slightly lower rotor alone fan pressure ratio at approach conditions. However, the small differences in fan performance at all fan conditions were considered too small to affect the fan acoustic performance.

  1. Miocene Current-Modified Submarine Fans

    Science.gov (United States)

    Arce Perez, L. E.; Snedden, J.; Fisher, W. L.

    2016-12-01

    In the southwestern Gulf of Mexico, new and newly reprocessed seismic data has revealed a series of large bedforms, with set thicknesses of 130 to 250 meters. These exhibit hummocky, oblique and shingled to parallel seismic clinoform reflections. This seismic package has a paleowater depth of 450 meters. Those shingled seismic reflections in offshore east Mexico are interpreted as contourite drift deposits. These Miocene-age contourites may be related to strong ocean bottom currents that modified submarine fans and transported sediment to the north. Those contourites were identified on older seismic data, but are better imaged and interpreted on this new data. Plans are to map out and investigate the origin and extent of fans and contourites that extends over a large area of the Gulf of Mexico. In the Early Miocene several submarine fans systems were formed by the sediment input related to orogenic activity in Mexico. Submarine fan development persisted into the Middle Miocene due to continued uplift and erosion of the Mexican landmass. Initial, contourites are small and close proximity to the deep-water fan. In the Late Miocene time, contourite drift field reached its maximum extent in the Mexican deepwater area, anchored on its southern end by a submarine mound. This mounded submarine fan is located in the offshore northeast Veracruz and can be linked to increased uplift and erosion of the Trans-Mexican volcanic belt. In the Miocene-Pliocene, the large contourite drift begins to diminish in size and scale and is moribund by the Pliocene, with establishment of oceanic circulation similar to the present day. This research is important to understand more about the Gulf of Mexico and also for the Miocene timeframe that is a key phase in the earth's history. The role of the change in bottom water flow during progressive closure of the equatorial seaway separating North and South America will also be investigated.

  2. Experimental alluvial fans: Advances in understanding of fan dynamics and processes

    Science.gov (United States)

    Clarke, Lucy E.

    2015-09-01

    Alluvial fans are depositional systems that develop because of a disparity between the upstream and downstream sediment transport capacity of a system, usually at the base of mountain fronts as rivers emerge from the constrained mountain area onto the plain. They are dynamic landforms that are prone to abrupt changes on a geomorphological (decades to centuries) time scale, while also being long-term deposition features that preserve sedimentary strata and are sensitive indictors of environmental change. The complexity of interactions between catchment characteristics, climate, tectonics, internal system feedbacks, and environmental processes on field alluvial fans means that it is difficult to isolate individual variables in a field setting; therefore, the controlled conditions afforded by experimental models has provided a novel technique to overcome some of these complexities. The use of experimental models of alluvial fans has a long history and these have been implemented over a range of different research areas utilising various experimental designs. Using this technique, important advances have been made in determining the primary factors influencing fan slope, understanding of avulsion dynamics, identifying autogenic processes driving change on fan systems independent of any change in external conditions, and the mechanics of flow and flood risk on alluvial fans, to name a few. However, experiments cannot be carried out in isolation. Thus, combining the findings from experimental alluvial fans with field research and numerical modelling is important and, likewise, using these techniques to inform experimental design. If this can be achieved, there is potential for future experimental developments to explore key alluvial fan issues such as stratigraphic preservation potential and simulating extra terrestrial fan systems.

  3. Middle and late quaternary oceanography and climatology of the Zaire-Congo fan and the adjacent Eastern Angola basin

    Science.gov (United States)

    Jansen, J. H. F.; Van Weering, T. C. E.; Gieles, R.; Van Iperen, J.

    La stratigraphie quaternaire du delta profond du Zaïre est établie sur la base des variations verticales des teneurs en carbonate, de l'analyse micropalaéontologique et des datations 14C et 230Th de 33 carottes. La vitesse des accumulations carbonatées et non carbonatées considérée en même temps que la conservation des carbonates nous conduit à distinguer les trois principaux facteurs à l'origine des concentrations en carbonate: production, dissolution et dilution par les particules non carbonatées. Les plus fortes productions carbonatées interviennent pendant les optima climatiques des interglaciaires tandis que les plus petites teneurs en carbonates sont probablement aussi liées à une augmentation de l'accumulation calcaire. Les fluctuations sont amplifiées par les effects de la dissolution qui est intense pendant les glaciaires et par les changements du rythme de la sédimentation terrigène. Dans la partie centrale du delta profond, un lobe de forte production carbonatée est localisé en permanence, il n'est pas associé à une zone de forte production de phytoplancton. Ce lobe est la conséquence d'un fort développement du zooplancton qui, pendant l'Holocène et les périodes interglaciaires, se multiplie à partir de cette floraison côtière de phytoplancton. Pendant les glaciaires, l'intensification de la circulation océanique déplace la zone des courants ascendants vers la latitude du delta du Zaïre. Dans deux carottes voisines de la bordure externe du plateau, une forte production en carbonates est observée entre 27 000 et 15 400 ans BP, elle est liée aux courants ascendants provoqués par l'intensification du courant de Benguela, et à une diminution de la sédimentation non carbonatée de de l'enfouissement du carbone organique à ˜ 14 500 ans BP. Une forte accumulation carbonatée se prolonge jusqu'à ˜12 500 ans BP, ce qui résulte un pic de conservation carbonatée à 14 000 ans BP qui n'est pas lié à un phénomène océanique. Une bréve intensification du compensation des carbonates et de la lysocline interviennent à des profondeurs moins grandes (4400 m et 3800 m) pendant les périodes glaciaires que de nos jours (5600 m et 4800 m). Les deux profondeurs des phases interglaciaires sont plus proches des profondeurs des phases glaciaires que de l'Holocène en fonction des dissolutions post-sédimentaires qui sont intervenues pendant les épisodes glaciaires consécutifs. L'hydrographie du Bassin de l'Angola n'apporte pas de preuves quant à des fluctuations des eaux profondes antarctiques qui auraient provoqué des cycles de dissolution des carbonates du Quaternaire de ce Bassin.

  4. Homophobia, heteronormativity, and slash fan fiction

    Directory of Open Access Journals (Sweden)

    April S. Callis

    2016-09-01

    Full Text Available I analyze the relationship between homophobia/heteronormativity and slash fan fiction. Through reading and coding almost 6,000 pages of Kirk/Spock fan fiction written from 1978 to 2014, I illuminate shifts in how normative gender and sexuality are portrayed by K/S authors. Writers of K/S, while ostensibly writing about the 23rd century, consciously or unconsciously include cultural norms from the 20th and 21st centuries. Thus, slash becomes a lens through which readers can view a decrease in both homophobia and heteronormativity in US culture over the past several decades.

  5. What Controls Runoff Ratios in the Congo Basin?

    Science.gov (United States)

    Durand, M. T.; Wei, R.

    2014-12-01

    As the second-largest river globally, the Congo is a critical part of large-scale water, energy, and carbon cycles, and thus has a significant influence on regional climate. The runoff ratio is a coefficient relating runoff to precipitation; it is a parameter that integrates and summarizes upstream hydrologic processes. The Budyko equation depicts the expected partitioning of precipitation (P) into evapotranspiration (E) and runoff (R): P=R+E. It is hypothesized that radiation and precipitation are primary controls of the partitioning process; the effects of the surface control (e.g. soil and slope) are implicitly assumed to be minor. In this study, we explored thirty years of data in the Congo River basin. We will correlate the runoff ratio to a variety of factors, including precipitation, radiation and surface controls (e.g. soil, slope). Global Precipitation Climatology Project (GPCP) by pentad precipitation was used as primary precipitation data, and Climatic Research Unit (CRU) by data was used for comparison. For discharge and drainage area were derived from Global Runoff Data Centre (GRDC), and net radiation is from NASA Earth Observatory. Congo sub basins are analyzed as well. Interannual variability in the runoff ratio for the Congo basin ranged from 0.2 to 0.3, but was generally uncorrelated with precipitation. Runoff is generally uncorrelated with precipitation, whereas evapotranspiration calculated as residual (P-R) is highly correlated with precipitation, with E ranging from 1000 to 1300 mm per year, and P explaining 85% of the variance. Spatial variability was explored by analysis of long-term mean runoff ratio for 10 sub-basins. Spatially, both R and runoff ratio are highly correlated with P, with P explaining 59% of the variance in the runoff ratio. Physical mechanisms to explain these results are explored, and the implications for the Congo's role in partitioning rainfall over sub-Saharan Africa are discussed.

  6. Fan fiction metadata creation and utilization within fan fiction archives: Three primary models

    Directory of Open Access Journals (Sweden)

    Shannon Fay Johnson

    2014-09-01

    Full Text Available Issues related to searchability and ease of access have plagued fan fiction since its inception. This paper discusses the predominate forms of fan-mediated indexing and descriptive metadata, commonly referred to as folksonomy or tagging, and compares the benefits and disadvantages of each model. These models fall into three broad categories: free tagging, controlled vocabulary, and hybrid folksonomy. Each model has distinct advantages and shortcomings related to findability, results filtering, and creative empowerment. Examples for each are provided. Possible ramifications to fan fiction from improved metadata and access are also discussed.

  7. Experiencing fan activism: Understanding the power of fan activist organizations through members' narratives

    Directory of Open Access Journals (Sweden)

    Neta Kligler-Vilenchik

    2012-06-01

    Full Text Available Fan activism, forms of civic engagement and political participation growing out of experiences of fandom, is a powerful mode of mobilization, particularly for young people. Building on 40 interviews with members of two organizations representing different configurations of fan activism, this article discusses three emerging elements that are key to the experience of membership in such groups. We suggest that the strength of fan activist groups builds on successfully combining these elements: two that are common to fandom, shared media experiences and a sense of community, and one that is traditionally ascribed to volunteerism and activism, the wish to help.

  8. Alluvial Fan Study Submission for UMATILLA COUNTY, OREGON

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Alluvial fan study data as defined in FEMA Guidelines and Specifications, Appendix G: Guidance for Alluvial Fan Flooding Analyses and Mapping

  9. Improving Fan System Performance: A Sourcebook for Industry

    Energy Technology Data Exchange (ETDEWEB)

    None

    2003-04-01

    This is one of a series of sourcebooks on motor-driven equipment produced by the Industrial Technologies Program. It provides a reference for industrial fan systems users, outlining opportunities to improve fan system performance.

  10. REDD+ Policy Approaches in the Congo Basin: A Comparative Analysis of Cameroon and the Democratic Republic of Congo (DRC

    Directory of Open Access Journals (Sweden)

    Kalame Fobissie

    2014-09-01

    Full Text Available The Congo Basin forests are a prime location for implementing REDD+. National REDD+ policy processes are ongoing and many REDD+ pilot initiatives are being demonstrated. However, the level of national engagement, progress and distribution of REDD+ activities varies considerably in the different Congo Basin countries. This study therefore uses a set of criteria to assess national and international policy initiatives and approaches for advancing REDD+ implementation in Cameroon and the Democratic Republic Congo (DRC, two countries where more than two thirds of the Congo Basin forests are concentrated. Our findings show that (i both countries have shown the highest political presence at the international climate negotiations but DRC has invested more in the size of its delegation and side events; (ii REDD+ donors, initiatives, and funding are disproportionately skewed towards DRC making it technically more advanced; (iii the high political interest and institutional reforms in DRC favors private sector investments in REDD+ programs; and (iv the REDD+ policy process is internally-driven in Cameroon with a strong national ownership, while it is externally-driven in DRC with weak national ownership. To advance REDD+, the government of DRC should embark on capacity building programs that ensure the transfer of REDD+ technical know-how from international to national actors while Cameroon needs to speed-up governance reforms and be more flexible in order to attract influential international REDD+ actors. This paper further provides specific recommendations.

  11. Fan action and political participation on "The Colbert Report"

    Directory of Open Access Journals (Sweden)

    Marcus Schulzke

    2012-06-01

    Full Text Available The Colbert Report merges the increasingly popular political satire genre with fan activism. The result is that the fan community helps to construct Colbert's malleable character and demonstrates symbolic power through its willingness to act. The fans are usually a nonpartisan force, acting to produce entertainment rather than substantive political change. However, this can be politically meaningful, as the fans' projects promote collective action, parallel political activities like voting and protesting, and encourage critical thinking about political information.

  12. Dead links, vaporcuts, and creativity in fan edit replication

    Directory of Open Access Journals (Sweden)

    Joshua Wille

    2015-09-01

    Full Text Available In my examination of a Star Wars prequel trilogy fan edit reportedly made by Topher Grace, I introduce the term vaporcut to describe fan edits with reputations that may generate critical discourse but that are not publicly released. I explore the ways some fan editors attempt to recreate intangible projects but inevitably produce variant works that reflect their own creative perspectives.

  13. Star Trek Rerun, Reread, Rewritten: Fan Writing as Textual Poaching.

    Science.gov (United States)

    Jenkins III, Henry

    1988-01-01

    Discusses women who write fiction and fan literature based on the "Star Trek" universe, outlining how Star Trek fans force the primary text to accommodate alternate interests. Also considers the issue of literary property in light of the moral economy of the fan community that shapes the range of permissible retellings of the program…

  14. Fan Stall Flutter Flow Mechanism Studied

    Science.gov (United States)

    Lepicovsky, Jan

    2002-01-01

    Modern turbofan engines employ a highly loaded fan stage with transonic or low-supersonic velocities in the blade-tip region. The fan blades are often prone to flutter at off-design conditions. Flutter is a highly undesirable and dangerous self-excited mode of blade oscillations that can result in high-cycle fatigue blade failure. The origins of blade flutter are not fully understood yet. Experimental data that can be used to clarify the origins of blade flutter in modern transonic fan designs are very limited. The Transonic Flutter Cascade Facility at the NASA Glenn Research Center was developed to experimentally study the details of flow mechanisms associated with fan flutter. The cascade airfoils are instrumented to measure high-frequency unsteady flow variations in addition to the steady flow data normally recorded in cascade tests. The test program measures the variation in surface pressure in response to the oscillation of one or more of the cascade airfoils. However, during the initial phases of the program when all airfoils were in fixed positions, conditions were found where significant time variations in the pressures near the airfoil leading edges could be observed.

  15. Acoustic analysis of a computer cooling fan

    Science.gov (United States)

    Huang, Lixi; Wang, Jian

    2005-10-01

    Noise radiated by a typical computer cooling fan is investigated experimentally and analyzed within the framework of rotor-stator interaction noise using point source formulation. The fan is 9 cm in rotor casing diameter and its design speed is 3000 rpm. The main noise sources are found and quantified; they are (a) the inlet flow distortion caused by the sharp edges of the incomplete bellmouth due to the square outer framework, (b) the interaction of rotor blades with the downstream struts which hold the motor, and (c) the extra size of one strut carrying electrical wiring. Methods are devised to extract the rotor-strut interaction noise, (b) and (c), radiated by the component forces of drag and thrust at the leading and higher order spinning pressure modes, as well as the leading edge noise generated by (a). By re-installing the original fan rotor in various casings, the noises radiated by the three features of the original fan are separated, and details of the directivity are interpreted. It is found that the inlet flow distortion and the unequal set of four struts make about the same amount of noise. Their corrections show a potential of around 10-dB sound power reduction.

  16. Generalized sorting profile of alluvial fans

    Science.gov (United States)

    Miller, Kimberly Litwin; Reitz, Meredith D.; Jerolmack, Douglas J.

    2014-10-01

    Alluvial rivers often exhibit self-similar gravel size distributions and abrupt gravel-sand transitions. Experiments suggest that these sorting patterns are established rapidly, but how—and how fast—this convergence occurs in the field is unknown. We examine the establishment of downstream sorting patterns in a kilometer-scale alluvial fan. The sharp transition from canyon to unconfined, channelized fan provides a well-defined boundary condition. The channel changes from deep and entrenched at the fan apex to shallow and depositional over a short distance, exhibiting nonequilibrium behavior. The resulting gravel-fining profile is not self-similar; the particle size distribution narrows until approximate equal mobility is achieved. Downfan, the gravel-sand transition appears to exhibit a self-similar form; field and laboratory data collapse when downstream distance is normalized by the location of the transition. Results suggest a generalized sorting profile for alluvial fans as a consequence of the threshold of motion and nonequilibrium channels.

  17. Fan Affinity Laws from a Collision Model

    Science.gov (United States)

    Bhattacharjee, Shayak

    2012-01-01

    The performance of a fan is usually estimated using hydrodynamical considerations. The calculations are long and involved and the results are expressed in terms of three affinity laws. In this paper we use kinetic theory to attack this problem. A hard sphere collision model is used, and subsequently a correction to account for the flow behaviour…

  18. Test particle acceleration in torsional fan reconnection

    Science.gov (United States)

    Hosseinpour, M.

    2014-12-01

    Magnetic reconnection is understood to be a potential mechanism for particle acceleration in astrophysical and space plasmas, especially in solar flares. Torsional fan reconnection is one of the proposed mechanisms for steady-state three-dimensional (3D) magnetic reconnection. By using the magnetic and electric fields for `torsional fan reconnection', the features of test particle acceleration with input parameters for the solar corona are investigated numerically. We show that torsional fan reconnection is potentially an efficient particle accelerator and a proton can gain up to tens of MeV of kinetic energy within only a few milliseconds. Although the final kinetic energy of the accelerated particle depends on the injection position but there exists only one scenario for the particle's trajectory with different initial positions in which the particle is accelerated on the fan plane. Moreover, adopting either spatially uniform or non-uniform localized plasma resistivity does not much influence the features of trajectory. These results are compared with those of torsional spine reconnection.

  19. Fan Affinity Laws from a Collision Model

    Science.gov (United States)

    Bhattacharjee, Shayak

    2012-01-01

    The performance of a fan is usually estimated using hydrodynamical considerations. The calculations are long and involved and the results are expressed in terms of three affinity laws. In this paper we use kinetic theory to attack this problem. A hard sphere collision model is used, and subsequently a correction to account for the flow behaviour…

  20. Fan Ky不等式的一个新改进%A New Improvement of Fan Ky's Inequality

    Institute of Scientific and Technical Information of China (English)

    黄政; 高明哲; 徐景实

    2010-01-01

    利用Gram矩阵的正定性和可变单位向量建立了Fan Ky不等式的一个新的改进,并且建立了反向Fan Ky不等式.对于非奇异矩阵,得到了Fan Ky不等式以及反向Fan Ky不等式的推广.

  1. Regenerative Blower for EVA Suit Ventilation Fan

    Science.gov (United States)

    Izenson, Michael G.; Chen, Weibo; Paul, Heather L.

    2010-01-01

    Portable life support systems in future space suits will include a ventilation subsystem driven by a dedicated fan. This ventilation fan must meet challenging requirements for pressure rise, flow rate, efficiency, size, safety, and reliability. This paper describes research and development that showed the feasibility of a regenerative blower that is uniquely suited to meet these requirements. We proved feasibility through component tests, blower tests, and design analysis. Based on the requirements for the Constellation Space Suit Element (CSSE) Portable Life Support System (PLSS) ventilation fan, we designed the critical elements of the blower. We measured the effects of key design parameters on blower performance using separate effects tests, and used the results of these tests to design a regenerative blower that will meet the ventilation fan requirements. We assembled a proof-of-concept blower and measured its performance at sub-atmospheric pressures that simulate a PLSS ventilation loop environment. Head/flow performance and maximum efficiency point data were used to specify the design and operating conditions for the ventilation fan. We identified materials for the blower that will enhance safety for operation in a lunar environment, and produced a solid model that illustrates the final design. The proof-of-concept blower produced the flow rate and pressure rise needed for the CSSE ventilation subsystem while running at 5400 rpm, consuming only 9 W of electric power using a non-optimized, commercial motor and controller and inefficient bearings. Scaling the test results to a complete design shows that a lightweight, compact, reliable, and low power regenerative blower can meet the performance requirements for future space suit life support systems.

  2. Psychoacoustic study on contribution of fan noise to engine noise

    Science.gov (United States)

    Zhang, Junhong; Liu, Hai; Bi, Fengrong; Ni, Guangjian; Zhang, Guichang; Lin, Jiewei; Yu, Hanzhengnan

    2012-07-01

    There are more researches on engine fan noise control focusing on reducing fan noise level through optimizing fan structure, and a lot of research achievements have been obtained. However, researches on the effect of fan noise to engine noise quality are lacking. The influences of the effects of fan structure optimization on the engine noise quality are unclear. Thus, there will be a decline in fan noise level, but the deterioration of engine noise quality. Aiming at the above problems, in consideration of fan structure design and engine noise quality, an innovative method to analyze the contribution of fan noise to engine noise quality using psychoacoustic theory is proposed. The noises of diesel engine installing different cooling fans are measured by using the acoustic pressure method. The experiment results are regarded as analysis samples. The model of sensory pleasantness is used to analyze the sound quality of a diesel engine with different cooling fans. Results show that after installing 10-blade fan in medium diameter the sensory pleasantness at each test point is increased, and the increase is 13.53% on average, which indicate the improvement of the engine noise quality. In order to verify the psychoacoustical analysis, the subjective assessment is carried out. The test result shows the noise quality of engine installed 10-blade fan in medium diameter is most superior. 1/3 octave frequency spectrum analysis is used to study the reason of the improvement of engine noise quality. It is found that after installing proper cooling fan the sound pressure level below 400 Hz are obviously increased, the frequency assignment and spectral envelope are more reasonable and a proper cooling fan can optimize the spectrum structure of the engine noise. The psychoacoustic study is applied in the contribution of fan noise to engine noise, and the idea of engine sound quality improvement through the structure optimization is proposed.

  3. Introduction of a Cooling-Fan Efficiency Index

    DEFF Research Database (Denmark)

    Schiavon, S.; Melikov, Arsen Krikor

    2009-01-01

    In a warm environment, air movement with elevated velocity is a well-known cooling strategy. The local air movement is typically generated by cooling fans (e.g., ceiling fan, table fans, etc.). Appearance, power input, and price are the main parameters considered today when purchasing cooling fans......, while cooling capacity and efficiency of energy use are unknown. To address this knowledge gap, this paper introduces the cooling-fan efficiency (CFE) index, defined as the ratio between the cooling effect (measured with a thermal manikin) generated by the device and its power consumption. The index...

  4. Democratic Republic of Congo A Fertile Ground for Instability in the Great Lakes Region States

    Science.gov (United States)

    2017-06-09

    DEMOCRATIC REPUBLIC OF CONGO-A FERTILE GROUND FOR INSTABILITY IN THE GREAT LAKES REGION STATES A thesis presented to the Faculty of...From - To) AUG 2016 – JUNE 2017 4. TITLE AND SUBTITLE Democratic Republic of Congo-A Fertile Ground for Instability in the Great Lakes Region ...caused instability and chaos in the eastern provinces of the Congo, known as the Great Lakes Region . The DRC holds a strategic geographical position

  5. Labeo rosae (Cypriniformes: Cyprinidae) in the Congo basin: a relict distribution or a historical introduction?

    Science.gov (United States)

    Van Steenberge, M; Gajdzik, L; Chilala, A; Snoeks, J; Vreven, E

    2014-11-01

    Labeo rosae, a species with a native range in Southern Africa, was discovered in the Congo basin by re-identification of two museum specimens previously identified as Labeo mesops. The occurrence of this species in the upper Congo implies a range extension of the species of more than 1000 km. Although the species' distribution is mirrored by that of some other Cypriniformes, its occurrence in the Congo might be due to introduction by humans.

  6. Fan-beam intensity modulated proton therapy

    Science.gov (United States)

    Hill, Patrick; Westerly, David; Mackie, Thomas

    2013-01-01

    Purpose: This paper presents a concept for a proton therapy system capable of delivering intensity modulated proton therapy using a fan beam of protons. This system would allow present and future gantry-based facilities to deliver state-of-the-art proton therapy with the greater normal tissue sparing made possible by intensity modulation techniques. Methods: A method for producing a divergent fan beam of protons using a pair of electromagnetic quadrupoles is described and particle transport through the quadrupole doublet is simulated using a commercially available software package. To manipulate the fan beam of protons, a modulation device is developed. This modulator inserts or retracts acrylic leaves of varying thickness from subsections of the fan beam. Each subsection, or beam channel, creates what effectively becomes a beam spot within the fan area. Each channel is able to provide 0–255 mm of range shift for its associated beam spot, or stop the beam and act as an intensity modulator. Results of particle transport simulations through the quadrupole system are incorporated into the MCNPX Monte Carlo transport code along with a model of the range and intensity modulation device. Several design parameters were investigated and optimized, culminating in the ability to create topotherapy treatment plans using distal-edge tracking on both phantom and patient datasets. Results: Beam transport calculations show that a pair of electromagnetic quadrupoles can be used to create a divergent fan beam of 200 MeV protons over a distance of 2.1 m. The quadrupole lengths were 30 and 48 cm, respectively, with transverse field gradients less than 20 T/m, which is within the range of water-cooled magnets for the quadrupole radii used. MCNPX simulations of topotherapy treatment plans suggest that, when using the distal edge tracking delivery method, many delivery angles are more important than insisting on narrow beam channel widths in order to obtain conformal target coverage

  7. Characterization of Composite Fan Case Resins

    Science.gov (United States)

    Dvoracek, Charlene M.

    2004-01-01

    The majority of commercial turbine engines that power today s aircraft use a large fan driven by the engine core to generate thrust which dramatically increases the engine s efficiency. However, if one of these fan blades fails during flight, it becomes high energy shrapnel, potentially impacting the engine or puncturing the aircraft itself and thus risking the lives of passengers. To solve this problem, the fan case must be capable of containing a fan blade should it break off during flight. Currently, all commercial fan cases are made of either just a thick metal barrier or a thinner metal wall surrounded by Kevlar-an ultra strong fiber that elastically catches the blade. My summer 2004 project was to characterize the resins for a composite fan case that will be lighter and more efficient than the current metal. The composite fan case is created by braiding carbon fibers and injecting a polymer resin into the braid. The resin holds the fibers together, so at first using the strongest polymer appears to logically lead to the strongest fan case. Unfortunately, the stronger polymers are too viscous when melted. This makes the manufacturing process more difficult because the polymer does not flow as freely through the braid, and the final product is less dense. With all of this in mind, it is important to remember that the strength of the polymer is still imperative; the case must still contain blades with high impact energy. The research identified which polymer had the right balance of properties, including ease of fabrication, toughness, and ability to transfer the load to the carbon fibers. Resin deformation was studied to better understand the composite response during high speed impact. My role in this research was the testing of polymers using dynamic mechanical analysis and tensile, compression, and torsion testing. Dynamic mechanical analysis examines the response of materials under cyclic loading. Two techniques were used for dynamic mechanical analysis

  8. Risky health seeking practice among pregnant women in rural Congo

    DEFF Research Database (Denmark)

    Hørby, Laila

    2007-01-01

    delays, Culture, Field and Capital, Democratic Republic Congo (DRC). Title: Risky health seeking practice, among pregnant women in rural Congo (DRC). Background Statement: Worldwide more than half a million women still die each year of pregnancy and childbirth related reasons. Most of these women live...... about 60 % of the women have a professional help at birth, and even fewer delivers in a health centre, which is far from the Unicef and WHO goal trying to combat high Maternal Mortality Rate (MMR). In the southern and rural part of DRC, is a small well equipped and well staffed dispensary and maternity...... professional assistance for normal pregnancy and delivery; delay in reaching an adequate medical facility, which includes accessibility, availability and cost of transportation and conditions of roads; and delays in obtaining the care needed to manage the situation. Following that I have analysed...

  9. Therapeutic management of Crimean-Congo haemorrhagic fever.

    Science.gov (United States)

    de la Calle-Prieto, Fernando; Martín-Quirós, Alejandro; Trigo, Elena; Mora-Rillo, Marta; Arsuaga, Marta; Díaz-Menéndez, Marta; Arribas, José Ramón

    2017-06-29

    Crimean-Congo haemorrhagic fever has been reported in more than 30 countries in Africa, Asia, the Middle East and Eastern Europe, with an increasing incidence in recent years, especially in Europe. Because no specific treatments have demonstrated efficacy, supportive treatment is essential, as well as the provision of a centre with the appropriate means to guarantee the safety of its healthcare professionals. Laboratory monitoring of thrombocytopenia, severe coagulopathy or liver failure is of critical importance. Patients with Crimean-Congo haemorrhagic fever should be admitted to High Level Isolation Units where appropriate biocontainment procedures can prevent nosocomial transmission through infected fluids or accidents with contaminated material. In case of high-risk exposures, early administration of ribavirin should be considered. Copyright © 2017. Publicado por Elsevier España, S.L.U.

  10. Improvement in performance of main ventilation fan for mines

    Energy Technology Data Exchange (ETDEWEB)

    Mukherjee, S.N. [Indian School of Mines, Dhanbad (India)

    2007-07-01

    This paper examined methods of improving the performance of main ventilation fans in mines. The basic principles of selecting and operating fans were reviewed, and methods of improving the energy efficiency of fans were evaluated. The study considered issues related to static efficiency, as well as curves and intersection points. Mine resistances were examined in relation to ventilation requirements at different phases of mine development. Flow losses and difficulties in producing accurate mathematical models of ventilation fans were also discussed. Fan operation set-points were reviewed. Details of tests conducted to determine the effects of the number of blades on fan performance were presented. The tests demonstrated the importance of incorporating cowl diffusers and guide vanes within the design of axial flow fans. The advantages of deblading were also discussed. 6 refs.

  11. Fluent-based numerical simulation of flow centrifugal fan

    Institute of Scientific and Technical Information of China (English)

    LI Xian-zhang

    2011-01-01

    Testing centrifugal fan flow field by physical laboratory is difficult because the testing system is complex and the workload is heavy, and the results observed by naked-eye deviates far from the actual value. To address this problem, the computational fluid dynamics software FLUENT was applied to establish three-dimensional model of the centrifugal fan. The numeral model was verified by comparing simulation data to experimental data. The pressure centrifugal fan and the speed changes in distribution in centrifugal fan was simulated by computational fluid dynamics software FLUENT. The simulation results show that the gas flow velocity in the impeller increases with impeller radius increase. Static pressure gradually increases when gas from the fan access is imported through fan impeller leaving fans.

  12. Numerical Aerodynamic Evaluation and Noise Investigation of a Bladeless Fan

    Directory of Open Access Journals (Sweden)

    mohammad jafari

    2015-01-01

    Full Text Available Bladeless fan is a novel fan type that has no observable impeller, usually used for domestic applications. Numerical investigation of a Bladeless fan via Finite Volume Method was carried out in this study. The fan was placed in center of a 4×2×2m room and 473 Eppler airfoil profile was used as cross section of the fan. Performance and noise level of the fan by solving continuity and momentum equations as well as noise equations of Broadband Noise Source (BNS and Ffowcs Williams and Hawkings (FW-H in both steady state and unsteady conditions were studied. Flow increase ratio of the fan was captured. Furthermore, BNS method could find outlet slit of the air as the main source of the noise generation. In order to validation of aeroacousticcode results, a simulation of noise for NACA 0012 airfoil via FW-H method was compared to experimental results and good agreement was obtained.

  13. Congophilicity (Congo red affinity) of different beta2-microglobulin conformations characterized by dye affinity capillary electrophoresis

    DEFF Research Database (Denmark)

    Heegaard, N H; Sen, J W; Nissen, Mogens Holst

    2000-01-01

    The amyloidogenic protein beta-microglobulin was characterized by affinity capillary electrophoresis (CE). CE could separate conformational variants of beta2-microglobulin and with the amyloid-specific dye Congo red as a buffer additive it was possible to measure different Congo red-affinities of......The amyloidogenic protein beta-microglobulin was characterized by affinity capillary electrophoresis (CE). CE could separate conformational variants of beta2-microglobulin and with the amyloid-specific dye Congo red as a buffer additive it was possible to measure different Congo red...

  14. The Democratic Republic of Congo: Background and Current Developments

    Science.gov (United States)

    2011-04-29

    Seko began in the city of Goma in the mid-1990s. The second rebellion in the late 1990s began also in eastern Congo. The root causes of the current...Democratic Rally (RCD- Goma ), the Movement for the Congolese Liberation (MLC), and representatives of the unarmed political groups. The agreement...from the border until a solution is found. In January 2007, several dozen rebel groups and the DRC government signed the Goma Accord, primarily

  15. Possible sexual transmission of Crimean-Congo hemorrhagic fever

    Directory of Open Access Journals (Sweden)

    Natalia Yurievna Pshenichnaya

    2016-04-01

    Full Text Available Three cases of family transmission of laboratory-confirmed Crimean-Congo hemorrhagic fever (CCHF among spouses are reported. These spouses had sexual contact at the end of the incubation period or during the early stage of the mild form of CCHF, without any hemorrhagic symptoms in the first infected spouse. This report demonstrates that sexual contact may represent a real risk of CCHF transmission, even if the patient only experiences mild symptoms.

  16. Opportunities for hydrologic research in the Congo Basin

    Science.gov (United States)

    Alsdorf, Douglas; Beighley, Ed; Laraque, Alain; Lee, Hyongki; Tshimanga, Raphael; O'Loughlin, Fiachra; Mahé, Gil; Dinga, Bienvenu; Moukandi, Guy; Spencer, Robert G. M.

    2016-06-01

    We review the published results on the Congo Basin hydrology and summarize the historic and ongoing research. Annual rainfall is ~1900 mm/yr along an east-west trend across the basin, decreasing northward and southward to ~1100 mm/yr. Historic studies using lysimeters, pans, and models suggest that the annual potential evapotranspiration varies little across the basin at 1100 to 1200 mm/yr. Over the past century, river discharge data have been collected at hundreds of stream gauges with historic and recent data at 96 locations now publicly available. Congo River discharge at Kinshasa-Brazzaville experienced an increase of 21% during the 1960-1970 decade in comparison to most other decades. Satellite altimetry measurements of high and low flows show that water levels in the "Cuvette Centrale" wetland are 0.5 m to 3.0 m higher in elevation than the immediately adjacent Congo River levels. Wetland water depths are shallow at about a meter and there does not appear to be many sizable channels across the "Cuvette"; thus, wetland flows are diffusive. Cuvette waters alone are estimated to emit about 0.5 Pg CH4 and CO2 equivalents/yr, an amount that is significant compared to global carbon evasions. Using these results, we suggest seven hypotheses that focus on the source of the Cuvette waters and how these leave the wetland, on the river discharge generated by historic rainfall, on the connection between climate change and the rainfall-runoff generated by the migrating "tropical rainbelt," on deforestation and hydroelectric power generation, and on the amount of carbon emitted from Congo waters.

  17. Crimean-Congo hemorrhagic fever in Iran and neighboring countries

    DEFF Research Database (Denmark)

    Chinikar, S; Ghiasi, Seyed Mojtaba; Hewson, R

    2010-01-01

    Crimean-Congo hemorrhagic fever (CCHF) is a zoonotic viral disease that is asymptomatic in infected livestock, but a serious threat to humans. Human infections begin with nonspecific febrile symptoms, but progress to a serious hemorrhagic syndrome with a case fatality rate of 2-50%. Although the ...... in Iran and neighboring countries and provide evidence of over 5000 confirmed cases of CCHF in a single period/season....

  18. A Q fever case mimicking crimean-congo haemorrhagic fever

    Directory of Open Access Journals (Sweden)

    O Karabay

    2011-01-01

    Full Text Available Coxiella burnetii is the bacterium that causes Q fever. Human infection is mainly transmitted from cattle, goats and sheep. The disease is usually self-limited. Pneumonia and hepatitis are the most common clinical manifestations. In this study, we present a case of Q fever from the western part of Turkey mimicking Crimean-Congo haemorrhagic fever (CCHF in terms of clinical and laboratory findings.

  19. Labour force participation of married women in China and Congo

    Institute of Scientific and Technical Information of China (English)

    KAMITEWOKO Edwige; JIN Xiang-rong

    2005-01-01

    The goal of this investigation was to find the major determinants of married women participation in the urban area labour force in Zhejiang (China) and Brazzaville (Congo). The methodology used in this study is correct and the resulting conclusion is that the participation of married women basically depends on her personal and family characteristics. Age, education,presence of additional adult in the family are important factors in Brazzaville and Zhejiang. However, the number of children significantly affects only Brazzaville urban married women.

  20. Nocturnal Fanning Suppresses Downy Mildew Epidemics in Sweet Basil.

    Science.gov (United States)

    Cohen, Yigal; Ben-Naim, Yariv

    2016-01-01

    Downy mildew is currently the most serious disease of sweet basil around the world. The oomycete causal agent Peronospora belbahrii requires ≥ 4h free leaf moisture for infection and ≥7.5h of water-saturated atmosphere (relative humidity RH≥95%) at night for sporulation. We show here that continued nocturnal fanning (wind speed of 0.4-1.5 m/s) from 8pm to 8am dramatically suppressed downy mildew development. In three experiments conducted during 2015, percent infected leaves in regular (non-fanned) net-houses reached a mean of 89.9, 94.3 and 96.0% compared to1.2, 1.7 and 0.5% in adjacent fanned net-houses, respectively. Nocturnal fanning reduced the number of hours per night with RH≥95% thus shortened the dew periods below the threshold required for infection or sporulation. In experiments A, B and C, the number of nights with ≥4h of RH≥95% was 28, 10 and 17 in the non-fanned net-houses compared to 5, 0 and 5 in the fanned net-houses, respectively. In the third experiment leaf wetness sensors were installed. Dew formation was strongly suppressed in the fanned net-house as compared to the non-fanned net-house. Healthy potted plants became infected and sporulated a week later if placed one night in the non-fanned house whereas healthy plants placed during that night in the fanned house remained healthy. Infected potted basil plants sporulated heavily after one night of incubation in the non-fanned house whereas almost no sporulation occurred in similar plants incubated that night in the fanned house. The data suggest that nocturnal fanning is highly effective in suppressing downy mildew epidemics in sweet basil. Fanning prevented the within-canopy RH from reaching saturation, reduced dew deposition on the leaves, and hence prevented both infection and sporulation of P. belbahrii.

  1. Comparison of turbidite facies associations in modern passive-margin Mississippi fan with ancient active-margin fans

    Science.gov (United States)

    Shanmugam, G.; Moiola, R. J.; McPherson, J. G.; O'Connell, S.

    1988-07-01

    Our comparison of the modern passive-margin Mississippi fan (DSDP Leg 96) with ancient active-margin fans (e.g. Eocene Hecho Group, Spain) reveals major differences in turbidite facies associations (Mutti and Ricci Lucchi scheme) and in seismic characteristics in the lower fan area. The lower (outer) Mississippi fan is composed of channel (Facies B and F) and non-channel facies (C? and D), whereas ancient fans are characterized by non-channelized, thickening-upward, depositional lobe facies (C and D). An absence of depositional lobes in the lower Mississippi fan is also suggested by a lack of convex-upward (mounded) seismic reflections with bidirectional downlap. Continuous seismic reflections of the lower Mississippi fan may represent "sheet sands", but not those of true depositional lobes with mounded character. Extensive channelization in modern passive-margin fans appears to be a product of the lateral shifting of a major sinuous distributary system, developed as a consequence of low gradients and the transport of sediment with a relatively low sand/mud ratio. In contrast, channels in active-margin fans are short and of low sinuosity as a result of high gradients and the transport of sediment with a relatively high sand/mud ratio. The turbidite facies association scheme, which was developed exclusively from ancient active-margin fans, should be applied to mature passive-margin fans with qualifications because of the differences in spatial distribution of turbidite facies and their associations.

  2. Fanning the Optimal Breeze with an Abanico

    Science.gov (United States)

    Goon, Grace; Marthelot, Joel; Reis, Pedro; MIT EGS Lab Team

    Flexible hand-held fans, or abanicos, are universally employed as cooling devices that are both portable and sustainable. Their to and fro axial motion about one's hand generates an airflow that increases the evaporation rate near the skin and refreshes. We study this problem in the context of fluid-structure interaction, through precision model experiments. We first characterize the elastic properties of a semi-circular thin plates with various thickness and evaluate their aerodynamic performance in a custom built apparatus. The air velocity profile that results from the flapping motion of the fan is characterized for different driving conditions. A systematic variation of the geometric and elastic parameters, along with an exploration of the parameter space of the periodic driving motion (amplitude and frequency), allows us to establish optimal design and operational conditions for maximal output of the generated airflow, while minimizing the input power.

  3. Terrestrial Cosmogenic-Nuclide Dating of Alluvial Fans in Death Valley, California

    Science.gov (United States)

    Machette, Michael N.; Slate, Janet L.; Phillips, Fred M.

    2008-01-01

    Panamint Valley and over Wingate Wash. A remnant of ancient lake shoreline deposits that once extended across the Hanaupah Canyon fan constrains the timing and extent of the last deep cycle of Pleistocene Lake Manly. The lacustrine delta complex yields a 36Cl depth-profile date of 130 ka, which is consistent with deposition during a highstand of Lake Manly at the end of MIS 6. These deposits are presently at an altitude of about 30 meters above sea level (asl), which relates to a lake with a maximum depth of about 115 meters. Remnants of shoreline deposits at higher elevations on the southern margin of the Hanaupah Canyon fan complex are cut across older alluvium (unit Qao) and may be related to an MIS 6 highstand of at least 67 meters asl or, more likely, an older (MIS 8 or earlier) highstand that is poorly preserved and still undated in the valley. As part of our work on the west-side fans, we also dated an older phase of alluvial-fan deposits from the Trail Canyon fan complex, which is north of Hanaupah Canyon. A 36Cl depth-profile age of 170 ka suggests alluvial deposition of unit Qaio (older phase of Qao) took place prior to the MIS 6 highstand of Lake Manly. Knowing the absolute ages (or range in ages) of the intermediate-age (Qai) surfaces in Death Valley allows us to estimate the following rates of geologic processes: (1) a lateral slip rate of 5 millimeters per year for the northern Death Valley fault zone; (2) uplift of 50 meters in roughly the past 80,000 years for parts of the Mustard Canyon hills in east-central Death Valley; and (3) an estimated 10-40 m of dip-slip thrust movement on the Echo Canyon fault in Furnace Creek Canyon.

  4. Polarization-fan high-order harmonics

    Science.gov (United States)

    Fleischer, Avner; Bordo, Eliyahu; Kfir, Ofer; Sidorenko, Pavel; Cohen, Oren

    2017-02-01

    We predict high-order harmonics in which the polarization within the spectral bandwidth of each harmonic varies with frequency continuously and significantly. For example, the interaction of counter-rotating circularly-polarized bichromatic drivers having close central frequencies with isotropic gas leads to the emission of polarization-fan harmonics where each harmonic in the spectrum has the following property: it is nearly circularly-polarized in one tail of the harmonic peak, linear in the center of the peak and nearly circular with the opposite helicity in the opposite tail. Also, we show that polarization-fan high harmonics with modulated ellipticity are obtained when elliptical drivers are used. Polarization-fan harmonics are obtained as a result of multiple (at least two) head-on recollisions of electrons with their parent ions occurring from different angles in a two-dimensional plane. The use of bichromatic drivers with close central frequencies largely preserves the single-cycle, single-atom and macroscopic physics of ‘ordinary’ high harmonic generation, where both the driver and high harmonics are linearly polarized. Thus, it should offer several attracting features, including (i) a direct route for extending the maximal photon energy of observed helical high harmonics to keV by using bichromatic drivers only in the mid-IR region and (ii) utilizing phase matching methods that were developed for ‘ordinary’ high harmonic generation driven by quasi-monochromatic pulses (e.g. pressure tuning phase matching). These polarization-fan harmonics may be utilized for exploring non-repetitive ultrafast chiral phenomena, e.g. dynamics of magnetic domains, in a single shot.

  5. Gigapixel Images Connect Sports Teams with Fans

    Science.gov (United States)

    2013-01-01

    Technology developed at Ames Research Center to take high-resolution imagery on Mars is now being used in baseball stadiums across the country. New York City-based Major League Baseball Advanced Media LP customized the platform to accommodate in-game shots that capture nearly the whole stadium. Fans navigate the photos online and tag themselves and their friends using social media tools.

  6. Modelling the Congo basin ecosystems with a dynamic vegetation model

    Science.gov (United States)

    Dury, Marie; Hambuckers, Alain; Trolliet, Franck; Huynen, Marie-Claude; Haineaux, Damien; Fontaine, Corentin M.; Fayolle, Adeline; François, Louis

    2014-05-01

    The scarcity of field observations in some parts of the world makes difficult a deep understanding of some ecosystems such as humid tropical forests in Central Africa. Therefore, modelling tools are interesting alternatives to study those regions even if the lack of data often prevents sharp calibration and validation of the model projections. Dynamic vegetation models (DVMs) are process-based models that simulate shifts in potential vegetation and its associated biogeochemical and hydrological cycles in response to climate. Initially run at the global scale, DVMs can be run at any spatial scale provided that climate and soil data are available. In the framework of the BIOSERF project ("Sustainability of tropical forest biodiversity and services under climate and human pressure"), we use and adapt the CARAIB dynamic vegetation model (Dury et al., iForest - Biogeosciences and Forestry, 4:82-99, 2011) to study the Congo basin vegetation dynamics. The field campaigns have notably allowed the refinement of the vegetation representation from plant functional types (PFTs) to individual species through the collection of parameters such as the specific leaf area or the leaf C:N ratio of common tropical tree species and the location of their present-day occurrences from literature and available database. Here, we test the model ability to reproduce the present spatial and temporal variations of carbon stocks (e.g. biomass, soil carbon) and fluxes (e.g. gross and net primary productivities (GPP and NPP), net ecosystem production (NEP)) as well as the observed distribution of the studied species over the Congo basin. In the lack of abundant and long-term measurements, we compare model results with time series of remote sensing products (e.g. vegetation leaf area index (LAI), GPP and NPP). Several sensitivity tests are presented: we assess consecutively the impacts of the level at which the vegetation is simulated (PFTs or species), the spatial resolution and the initial land

  7. Fan edits and the legacy of The Phantom Edit

    Directory of Open Access Journals (Sweden)

    Joshua Wille

    2014-09-01

    Full Text Available A fan edit can generally be defined as an alternative version of a film or television text created by a fan. It offers a different viewing experience, much as a song remix offers a different listening experience. The contemporary wave of fan edits has emerged during the remix zeitgeist of digital media and at a time when digital video editing technology has become more affordable and popular. The increasing number of alternative versions of films and the works of revisionist Hollywood filmmakers such as George Lucas have contributed to a greater public understanding of cinema as a fluid medium instead of one that exists in a fixed form. The Phantom Edit (2000, a seminal fan edit based on Lucas's Star Wars Episode I: The Phantom Menace (1999, inspired new ranks of fan editors. However, critics have misunderstood fan edits as merely the work of disgruntled fans. In order to provide a critical and historical basis for studies in fan editing as a creative practice, I examine previous interpretations of fan edits in the context of relevant contemporary works, and I use an annotated chronology of The Phantom Edit to trace its influence on subsequent fan editing communities and uncover their relationship with intellectual property disputes.

  8. "Emotions-Only" versus "Special People": Genre in fan discourse

    Directory of Open Access Journals (Sweden)

    Louisa Ellen Stein

    2008-09-01

    Full Text Available This essay looks at genre as a complex set of discursive threads running unevenly through production, TV text, and fan reception. Through a case study of the reception of fan favorite Roswell, this essay interrogates the role of genre in spectatorship. In its mixing of teen and science fiction elements, Roswell trod upon contested generic spaces, eliciting strong reaction from its viewers. Connections between genre and gender came to the fore, as producer commentary linked science fiction with male audiences and teen romance with female audiences. Fans responded with analyses that greatly complicated and at times overtly rejected industrial suppositions regarding the gendered work of genre. Through these fan conversations, we can witness the complexity of genre as discursive thread moving through not only TV texts but also multivariant fan responses. I intend this essay to work at two levels. My analysis of fan responses to Roswell models the possibilities of a close study of genre discourse. At the same time, my case study probes the nature of genre in fan engagement, as genre discourses intersect with other fan concerns such as character identification, perceptions of textual quality, and questions of gender representation. While we cannot necessarily look to fan accounts for proof of how viewers engage with genre, they do tell us how fans frame their engagement with genre, how they incorporate genre into their performance of fannishness, and how they perform and thus enact genre itself as a shared cultural process.

  9. The aerodynamics of a wind-tunnel fan

    Science.gov (United States)

    Corson, Blake W

    1941-01-01

    The vortex blade-element theory modified to apply to an axial fan working in a duct is reviewed. Thrust and power coefficients for a fan are identified with the corresponding coefficients for airplane propellers. The relation of pressure produced by the fan to the blade-element coefficients is developed. The distribution of axial velocity of fluid through a fan is assumed to be controlled by the fan itself. The radial distribution of tangential velocity imported by the fan to fluid moving through the fan is shown to be independent of the axial-velocity distribution. A nondimensional coefficient, designated the rotation constant, is introduced. This constant is based solely upon design information. The use of the rotation constant in simplifying the design of a fan for a specific operating condition is demonstrated. Based on the use of the rotation constant, a graphical method is outlined by which the performance of a given fan in a given wind tunnel may be predicted and by which the distributions of axial velocity of the fluid through the fan under various operating conditions may be established.

  10. A Fan-tastic Alternative to Bulbs: Learning Circuits with Fans

    Science.gov (United States)

    Ekey, Robert; Edwards, Andrea; McCullough, Roy; Reitz, William; Mitchell, Brandon

    2017-01-01

    The incandescent bulb has been a useful tool for teaching basic electrical circuits, as brightness is related to the current or power flowing through a bulb. This has led to the development of qualitative pedagogical treatments for examining resistive combinations in simple circuits using bulbs and batteries, which were first introduced by James Evans and thoroughly expanded upon by McDermott and others. This paper argues that replacing bulbs with small computer fans leads to similar, if not greater, insight of experimental results that can be qualitatively observed using a variety of senses. The magnitude of current through a fan is related to the frequency of the rotating fan blades, which can be seen, heard, and felt by the students. Experiments using incandescent bulbs only utilize vision, which is not ideal as the human eyes' perception of brightness is skewed because the response to light intensity is logarithmic rather than linear.

  11. Future Discounting in Congo Basin Hunter-Gatherers Declines with Socio-Economic Transitions.

    Directory of Open Access Journals (Sweden)

    Gul Deniz Salali

    Full Text Available Humans have a tendency to discount the future; that is we value small, short-term rewards over larger, long-term rewards. The degree of future discounting, however, changes in response to socio-ecological factors. Here, we study Mbendjele BaYaka hunter-gatherers of northern Congo and their farmer neighbours to investigate adaptations in inter-temporal preferences in humans. We argue that in immediate-return systems, where food storage is absent and egalitarianism is enforced through levelling mechanisms, future discounting is an adaptive strategy to prevent wealth accumulation and the emergence of hierarchies. This ensures food sharing and allows for survival in unpredictable environments where there is risk of an energy shortfall. On the other hand, when food storage is made possible by the emergence of agriculture or as seen in some delayed-return hunter-gatherer populations, wealth accumulation, hierarchies and lower discount rates become the adaptive strategy. Therefore, individuals in immediate-return, egalitarian societies will discount the future more than those in non-egalitarian, delayed-return societies. Consistent with the predictions we found that market integration and socio-economic transitions decrease the future discounting in Mbendjele hunter-gatherers. Our measures of socio-economic differences marked this transition in hunter-gatherers living in a logging town. The degree of future-discounting was the same between more market-integrated hunter-gatherers and their farmer neighbours.

  12. Sero-epidemiological survey of Crimean-Congo hemorrhagic fever virus in Tunisia

    Directory of Open Access Journals (Sweden)

    Wasfi Fares

    2016-01-01

    Full Text Available Crimean-Congo hemorrhagic fever (CCHF is a tick-borne disease associated with a high case fatality rate and transmitted mainly by Hyalomma marginatum. The geographical distribution of H. marginatum covers most of the Western Mediterranean basin. We aimed to investigate whether CCHF virus (CCHFv is circulating in Tunisia. Samples from unexplained acute febrile patients (n = 181 and a high risk group of humans, mainly slaughter workers (n = 38, were collected in the summer of 2014 and analyzed for exposure to CCHFv using serological tests and real-time RT-PCR. Ticks were collected from Northern and Southern Tunisia during May–June 2014 and examined for the presence of CCHFv by real-time RT-PCR. Of the 181 febrile patients, 5 showed only high titers of IgM suggesting a recent exposure to CCHFv. Among 38 slaughter workers, 2 had IgG anti-CCHFv responses yielding a seroprevalence of 5.2%. No CCHFv was detected in ticks and sera. Our results provide evidence of human exposure to CCHFv in Tunisia.

  13. Sero-epidemiological survey of Crimean-Congo hemorrhagic fever virus in Tunisia

    Science.gov (United States)

    Wasfi, Fares; Dowall, Stuart; Ghabbari, Tayssir; Bosworth, Andrew; Chakroun, Mohamed; Varghese, Anitha; Tiouiri, Hanene; Ben Jemaa, Mounir; Znazen, Abir; Hewson, Roger; Zhioua, Elyes; Letaief, Amel

    2016-01-01

    Crimean-Congo hemorrhagic fever (CCHF) is a tick-borne disease associated with a high case fatality rate and transmitted mainly by Hyalomma marginatum. The geographical distribution of H. marginatum covers most of the Western Mediterranean basin. We aimed to investigate whether CCHF virus (CCHFv) is circulating in Tunisia. Samples from unexplained acute febrile patients (n = 181) and a high risk group of humans, mainly slaughter workers (n = 38), were collected in the summer of 2014 and analyzed for exposure to CCHFv using serological tests and real-time RT-PCR. Ticks were collected from Northern and Southern Tunisia during May–June 2014 and examined for the presence of CCHFv by real-time RT-PCR. Of the 181 febrile patients, 5 showed only high titers of IgM suggesting a recent exposure to CCHFv. Among 38 slaughter workers, 2 had IgG anti-CCHFv responses yielding a seroprevalence of 5.2%. No CCHFv was detected in ticks and sera. Our results provide evidence of human exposure to CCHFv in Tunisia. PMID:26956221

  14. Seroepidemiology of Crimean Congo Hemorrhagic Fever in Slaughterhouse Workers in North Eastern Iran

    Directory of Open Access Journals (Sweden)

    M Zeinali

    2012-11-01

    Full Text Available Background: Crimean Congo Hemorrhagic Fever (CCHF is an acute febrile haemorrhagic disease. This study was conducted to ascertain the infection status amongst slaughterhouse workers in Iran's north-eastern provinces (Razavi and northern and southern Khorasan, so that analysis of the results could help clarification of the epidemiology of this disease in the aforementioned provinces and eastern regions of Iran.Methods: In this cross-sectional study, conducted in 2004 and 2005, 108 slaughterhouse workers from 24 cities of the three previously mentioned provinces were randomly entered into the study. An IgG specific ELISA test was carried out on the participants’ serum samples.Results: Sixteen out of 108 (14.8% participants under study were shown to have IgG against CCHF. The highest rate of infection was seen in Razavi Khorasan and southern Khorasan at 17.5% and 16.7%, respectively.Conclusion: The study showed a relatively high frequency of this disease amongst slaughterhouse workers in these provinces. Taking into account the small number of reported cases from these provinces, it would seem that more focus is required on primary diagnosis and on referral of suspected patients.

  15. Attending 22nd General Assembly of CONGO and World Summit on Information Society

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    <正>ACPAFFC delegation headed by its vice presi-dent Li Xiaolin attended the 22nd General Assembly of the Conference of NGOs (CONGO) and the World Summit on the Information Society in Geneva from December 4 to 12, 2003.CONGO, founded in

  16. Collaboration between Higher Education and Labor Market in Kinshasa, DR Congo

    Science.gov (United States)

    Etshim, Rachal

    2017-01-01

    The transition of new graduate students from school to the labor market in Democratic Republic of Congo has been a major topic for debate over the last twenty years. This study identifies the factors affecting collaboration between higher education and the labor market in Kinshasa, the Capital city of the Democratic Republic of Congo. Even though…

  17. Beam fanning effect and image storage in Ce: KNSBN crystal

    Institute of Scientific and Technical Information of China (English)

    LI PanLai; GUO QingLin; WANG ZhiJun; PANG LiBin; LIANG BaoLai

    2007-01-01

    A non-synchronously-numerating experimental system is applied in this research. The effect of the incident beam intensity Ⅰ and the beam incident angle θ on beam fanning effect is investigated with a singular beam incident on Ce:KNSBN crystal. The results show that the beam fanning effect strongly depends on Iand θ. The threshold effect of/for the beam fanning in Ce:KNSBN crystal is observed, and the threshold intensity of incident beam keeps the same value of 38.2 mW/cm2 for different θ, and the steady beam fanning intensity Ifsat reaches a peak at θ=15° under the same Ⅰ. In addition, the effect of the incident beam modulated on the beam fanning noise and holographic storage in Ce:KNSBN crystal is studied. And the results suggest that the beam fanning noise is effectively suppressed, and the quality of the reappearance image is greatly improved.

  18. Procedure for Balancing an Air Distribution System with Decentralised Fans

    DEFF Research Database (Denmark)

    Gunner, Amalie; Hultmark, Göran; Vorre, Anders

    2015-01-01

    of the fans. In conventional air distribution systems the fan provides the necessary pressure to overcome the resistance in the branch with the highest pressure resistance. This gives an unnecessary overpressure in the remaining branches that does not provide any useful purpose. In order to decrease the fan......This paper presents results from an on-going project concerning new design procedures for mechanical ventilation systems with low energy use. Conventional constant air volume (CAV) systems are usually balanced using flat plate dampers. The purpose of using balancing dampers is to intentionally...... pressure requirements the fan was dimensioned for the branch with the least pressure resistance. The decentralised fans then provided sufficient pressure to overcome the exact resistance in the corresponding branch. The results show that by using decentralised fans in duct systems instead of dampers...

  19. Procedure for Balancing an Air Distribution System with Decentralised Fans

    DEFF Research Database (Denmark)

    Gunner, Amalie; Hultmark, Göran; Vorre, Anders;

    2015-01-01

    This paper presents results from an on-going project concerning new design procedures for mechanical ventilation systems with low energy use. Conventional constant air volume (CAV) systems are usually balanced using flat plate dampers. The purpose of using balancing dampers is to intentionally...... flawed. This paper presents a new procedure for balancing of CAV systems in combination with decentralised fans. The new system was based on replacing the balancing dampers with decentralised fans. By replacing the balancing dampers with decentralised fans, airflows can be balanced by adjusting the speed...... of the fans. In conventional air distribution systems the fan provides the necessary pressure to overcome the resistance in the branch with the highest pressure resistance. This gives an unnecessary overpressure in the remaining branches that does not provide any useful purpose. In order to decrease the fan...

  20. Grain size trends reveal alluvial fan sensitivity to late Pleistocene climate change

    Science.gov (United States)

    Whittaker, A. C.; D'Arcy, M. K.; Roda Boluda, D. C.

    2015-12-01

    The effects of climate change on eroding landscapes and the sedimentary record remain poorly understood. The measurement of grain size fining rates in stream-flow dominated deposits provides one way to address this issue because, in principle, these trends embed important information about the dynamics of sediment routing systems and their sensitivities to external forcing. At a fundamental level, downstream fining is often driven by selective deposition of sediment. The relative efficiency of this process is determined by the physical characteristics of the input sediment supply and the spatial distribution of subsidence rate, which generates the accommodation necessary for mass extraction. Here, we measure grain size fining rates from apex to toe on two alluvial fan systems in northern Death Valley, California, which have well-exposed modern and 70 ka surfaces, where the long-term tectonic boundary conditions are known and where climatic variation over this time period is well-constrained. We integrate a self-similar gravel fraction fining model, based on selective sediment extraction, with cosmogenically-derived catchment erosion rates and gravel fining data, to estimate the change in sediment flux that occurred between 70 ka and the present day. Our results show that a 30 % decrease in average precipitation rate led to a 20 % decrease in sediment flux and a clear increase in the down-fan rate of fining. This supports existing landscape evolution models that relate a decrease in precipitation rate to a decrease in sediment flux, but implies that this relationship may be sub-linear. This study offers a new approach to applying grain size fining models to mountain catchments and their alluvial fan systems, and shows fan stratigraphy can be highly sensitive to climate changes over sensitivity is lost when sediment is remobilised and recycled over a time period longer than the duration of the climatic perturbation.

  1. On limited fan-in optimal neural networks

    Energy Technology Data Exchange (ETDEWEB)

    Beiu, V.; Makaruk, H.E. [Los Alamos National Lab., NM (United States); Draghici, S. [Wayne State Univ., Detroit, MI (United States). Vision and Neural Networks Lab.

    1998-03-01

    Because VLSI implementations do not cope well with highly interconnected nets the area of a chip growing as the cube of the fan-in--this paper analyses the influence of limited fan in on the size and VLSI optimality of such nets. Two different approaches will show that VLSI- and size-optimal discrete neural networks can be obtained for small (i.e. lower than linear) fan-in values. They have applications to hardware implementations of neural networks. The first approach is based on implementing a certain sub class of Boolean functions, IF{sub n,m} functions. The authors will show that this class of functions can be implemented in VLSI optimal (i.e., minimizing AT{sup 2}) neural networks of small constant fan ins. The second approach is based on implementing Boolean functions for which the classical Shannon`s decomposition can be used. Such a solution has already been used to prove bounds on neural networks with fan-ins limited to 2. They generalize the result presented there to arbitrary fan-in, and prove that the size is minimized by small fan in values, while relative minimum size solutions can be obtained for fan-ins strictly lower than linear. Finally, a size-optimal neural network having small constant fan-ins will be suggested for IF{sub n,m} functions.

  2. The Mechanical Impact of Aerodynamic Stall on Tunnel Ventilation Fans

    Directory of Open Access Journals (Sweden)

    A. G. Sheard

    2012-01-01

    Full Text Available This paper describes work aimed at establishing the ability of a tunnel ventilation fan to operate without risk of mechanical failure in the event of aerodynamic stall. The research establishes the aerodynamic characteristics of a typical tunnel ventilation fan when operated in both stable and stalled aerodynamic conditions, with and without an anti-stall stabilisation ring, with and without a “nonstalling” blade angle and at full, half, and one quarter design speed. It also measures the fan’s peak stress, thus facilitating an analysis of the implications of the experimental results for mechanical design methodology. The paper concludes by presenting three different strategies for tunnel ventilation fan selection in applications where the selected fan will most likely stall. The first strategy selects a fan with a low-blade angle that is nonstalling. The second strategy selects a fan with a high-pressure developing capability. The third strategy selects a fan with a fitted stabilisation ring. Tunnel ventilation system designers each have their favoured fan selection strategy. However, all three strategies can produce system designs within which a tunnel ventilation fan performs reliably in-service. The paper considers the advantages and disadvantages of each selection strategy and considered the strengths and weaknesses of each.

  3. K-pop Reception and Participatory Fan Culture in Austria

    Directory of Open Access Journals (Sweden)

    Sang-Yeon Sung

    2013-12-01

    Full Text Available K-pop’s popularity and its participatory fan culture have expanded beyond Asia and become significant in Europe in the past few years. After South Korean pop singer Psy’s “Gangnam Style” music video topped the Austrian chart in October 2012, the number and size of K-pop events in Austria sharply increased, with fans organizing various participatory events, including K-pop auditions, dance festivals, club meetings, quiz competitions, dance workshops, and smaller fan-culture gatherings. In the private sector, longtime fans have transitioned from participants to providers, and in the public sector, from observers to sponsors. Through in-depth interviews with event organizers, sponsors, and fans, this article offers an ethnographic study of the reception of K-pop in Europe that takes into consideration local interactions between fans and Korean sponsors, perspectives on the genre, patterns of social integration, and histories. As a case study, this research stresses the local situatedness of K-pop fan culture by arguing that local private and public sponsors and fans make the reception of K-pop different in each locality. By exploring local scenes of K-pop reception and fan culture, the article demonstrates the rapidly growing consumption of K-pop among Europeans and stresses multidirectional understandings of globalization.

  4. A measuring stand for a ducted fan aircraft propulsion unit

    Directory of Open Access Journals (Sweden)

    Hlaváček David

    2014-03-01

    Full Text Available The UL-39 ultra-light aircraft which is being developed by the Department of Aerospace Engineering, Faculty of Mechanical Engineering, Czech Technical University in Prague, is equipped with an unconventional ducted fan propulsion unit. The unit consists of an axial fan driven by a piston engine and placed inside a duct ended with a nozzle. This article describes the arrangement of a modernised measuring stand for this highly specific propulsion unit which will be able to measure the fan pressure ratio and velocity field in front of and behind the fan and its characteristic curve.

  5. BIOSORPTION OF CONGO RED BY HYDROGEN PEROXIDE TREATED TENDU WASTE

    Directory of Open Access Journals (Sweden)

    G. K. Nagda ، V. S. Ghole

    2009-07-01

    Full Text Available Solid wastes from agro-industrial operations can be recycled as non-conventional adsorbents if they are inert and harmless and reduce the cost of wastewater treatment. Tendu leaf Diospyros melanoxylon is the second largest forest product in India after timber and is exclusively used in making local cigarette called Bidi. Waste leaf cutting remaining after making cigarette was used in present study as a biosorbent for the removal of Congo red dye from aqueous solution. It was treated with hydrogen peroxide to obtain biosorbent with increased adsorption capacity. Batch type experiments were conducted to study the influence of different parameters such as pH, initial dye concentration and dosage of adsorbent on biosorption evaluated. The adsorption occured very fast initially and attains equilibrium within 60 min at pH= 6.2 and the equilibrium attained faster after hydrogen peroxide modification. Kinetic studies showed that the biosorption of Congo red on tendu waste followed pseudo-second-order rate equation. The data fitted well to Langmuir and Freundlich isotherm models. Comparison was done on the extent of biosorption between untreated and treated forms of the tendu waste. The maximum adsorption capacity for untreated tendu waste was found to be 46.95 mg/g, which was enhanced by 2.8 times after hydrogen peroxide treatment and was found to be 134.4 mg/g. The adsorption process was in conformity with Freundlich and Langmuir isotherms for Congo red adsorption from aqueous solution. The study demonstrated use of milder chemical treatment of tendu waste to obtain a biosorbent with enhanced dye removal capacity.

  6. Lightning climatology in the Congo Basin: methodology and first results

    Science.gov (United States)

    Kigotsi, Jean; Soula, Serge; Georgis, Jean-François; Barthe, Christelle

    2016-04-01

    The global climatology of lightning issued from space observations (OTD and LIS) clearly showed the maximum of the thunderstorm activity is located in a large area of the Congo Basin, especially in the Democratic Republic of Congo (DRC). The first goal of the present study is to compare observations from the World Wide Lightning Location Network (WWLLN) from the Lightning Imaging Sensor (LIS) over a 9-year period (2005-2013) in this 2750 km × 2750 km area. The second goal is to analyse the lightning activity in terms of time and space variability. The detection efficiency (DE) of the WWLLN relative to LIS has increased between 2005 and 2013, typically from about 1.70 % to 5.90 %, in agreement with previous results for other regions of the world. The mean monthly flash rate describes an annual cycle with a maximum between November and March and a minimum between June and August, associated with the ICTZ migration but not exactly symmetrical on both sides of the equator. The diurnal evolution of the flash rate has a maximum between 1400 and 1700 UTC, depending on the reference year, in agreement with previous works in other regions of the world. The annual flash density shows a sharp maximum localized in eastern DRC regardless of the reference year and the period of the year. This annual maximum systematically located west of Kivu Lake corresponds to that previously identified by many authors as the worldwide maximum which Christian et al. (2013) falsely attributed to Rwanda. Another more extended region within the Congo Basin exhibits moderately large values, especially during the beginning of the period analyzed. A comparison of both patterns of lightning density from the WWLLN and from LIS allows to validate the representativeness of this world network and to restitute the total lightning activity in terms of lightning density and rate.

  7. Background Report on Eastern Democratic Republic of the Congo

    Energy Technology Data Exchange (ETDEWEB)

    Warren, Tracy A [ORNL

    2011-05-01

    Each month, approximately 45,000 people die from violence, hunger, disease, and other effects of displacement as a result of war in the Democratic Republic of the Congo (DRC). The country is often said to be plagued by a 'resource curse.' During each period in history since its discovery by the West, the DRC has possessed the resources the world craves and the world has sought these without regard for the consequences to the Congolese people. The catastrophic consequences of Congo's history of natural resource exploitation are the direct and indirect death of millions of Congolese people. The current war in Congo is multi-causal in nature but explanations are often reduced to describing it as an ethic conflict based on objective grievance. Objective grievance such as inequality, ethnic tensions, land disputes, and lack of democracy do exist, but they are neither necessary nor sufficient to explain the cause of the violent conflict, and more importantly, they fall short in explaining why this conflict has continued for years. The reality is the conflict is an economic war in which the trade of conflict minerals, gold and the 3Ts (tin, tantalum, tungsten), is directly linked to the financial sustainability of the groups fighting each other in eastern DRC. Objective grievance is a by-product of the conflict, used to create a false but plausible moral justification to continue violence. This paper examines the history of conflict in the DRC and the socio-economic variables contributing to the current war fought over conflict minerals.

  8. A Case of Crimean-Congo Hemorrhagic Fever in Oman

    Directory of Open Access Journals (Sweden)

    Matllooba Al-Zadjali

    2013-05-01

    Full Text Available In the summer of June 2011, the first case of Crimean-Congo hemorrhagic fever (CCHF was observed in Oman since the last fifteen years. The first blood sample using reverse transcriptase polymerase chain reaction (PCR test were sent looking for CCHF, tick-borne encephalitis, dengue, Japanese encephalitis, Chikungunya and West Nile. All resulted as negative. The repeated serology for CCHF came strongly positive after five days from the initial negative test, and accordingly patient started on ribavirin and he responded to it. His condition improved dramatically.

  9. Tectonic controls on the geomorphic evolution of alluvial fans in the Piedmont Zone of Ganga Plain, Uttarakhand, India

    Indian Academy of Sciences (India)

    Pradeep K Goswami; Charu C Pant; Shefali Pandey

    2009-06-01

    The Piedmont Zone is the least studied part of the Ganga Plain.The northern limit of the Piedmont Zone is defined by the Himalayan Frontal Thrust (HFT)along which the Himalaya is being thrust over the alluvium of the Ganga Plain.Interpretation of satellite imagery,Digital Terrain Models (DTMs)and field data has helped in the identification and mapping of various morpho-tectonic features in the densely forested and cultivated Piedmont Zone in the Kumaun region of the Uttarakhand state of India.The Piedmont Zone has formed as a result of coalescing alluvial fans,alluvial aprons and talus deposits.The fans have differential morphologies and aggradation processes within a common climatic zone and similar litho-tectonic setting of the catchment area. Morphotectonic analysis reveals that the fan morphologies and aggradation processes in the area are mainly controlled by the ongoing tectonic activities.Such activities along the HFT and transverse faults have controlled the accommodation space by causing differential subsidence of the basin,and aggradation processes by causing channel migration,channel incision and shifting of depocentres.The active tectonic movements have further modified the landscape of the area in the form of tilted alluvial fan,gravel ridges,terraces and uplifted gravels.

  10. Extreme Loading of Aircraft Fan Blade

    CERN Document Server

    Datta, Dibakar

    2013-01-01

    The response of an aircraft fan blade manufactured by composites under the action of static and impact load has been studied in this report. The modeling and analysis of the geometry has been done using CASTEM 2007 version. For the quasi static analysis, the pressure has been incrementally applied until it satisfies the failure criteria. The deformed configuration, strain, Von-Mises stress, and the deflection of the blade have been studied. The response of the system e.g. deformation time history due to the impact of the projectile has been studied where the Newmark method for the dynamic problem has been implemented.

  11. Condensate Accretion in Shock Tube's Expansion Fan

    Science.gov (United States)

    Mezonlin, Ephrem-Denis; DeSilva, Upul P.; Hunte, F.; Johnson, Joseph A., III

    1997-01-01

    It has been shown that turbulence and temperature influence the droplet sizes in expansion fan induced condensation by studying the Rayleigh scattering from one port in our shock tube's test section. We have modified our set-up so as to allow, using two ports, the real time measurement of the influence of turbulence and temperature on the rate at which these droplets grow. To do this, we looked at the Rayleigh scattering from two different ports for ten Reynolds numbers at five different temperatures. We modeled the time of flight of droplets, using the equations of one-dimensional gas dynamics and the measured shock wave speed in shock tube's driven section.

  12. Through flow analysis of pumps and fans

    Science.gov (United States)

    Neal, A. N.

    1980-08-01

    Incompressible through flow calculations in axial, mixed and centrifugal flow pumps and fans are described. An iterative scheme is used. A simple blade to blade model is applied on the surfaces of revolution defined by the meridional streamlines. This defines the fluid properties and the mean stream surface (S2 surface) for the next meridional solution. A computer program is available allowing the method to be applied for design purposes. APL is used for input and output and FORTRAN IV for computation. A typical calculation requires 30 sec of Univac 1100 time.

  13. Case study of French and Spanish fan reception of Game of Thrones

    Directory of Open Access Journals (Sweden)

    Mélanie Bourdaa

    2015-06-01

    Full Text Available The reception of the American TV show Game of Thrones (2011– by French and Spanish fans and nonfans is addressed via a qualitative methodology, the goal of which is to understand how European viewers perceive themselves as fans and what it means for them to be fans. Analysis of characteristics of a specifically European reception helps us learn what fan studies tell us about fans and what fans really think about fandoms.

  14. The Congo Clawless Otter: State of Knowledge and Needs for Further Research

    Directory of Open Access Journals (Sweden)

    Helene Jacques

    2004-01-01

    Full Text Available Among the 4 African otter species, the Congo clawless otter (Aonyx congicus is the least known because of the remoteness of its Central African equatorial rainforest range. Its distribution, status, and biology in the field are now being investigated and preliminary results are introduced. Two missions in Gabon, followed by one in Congo, allowed us to gather local information, to find tracks and to identify otters in their habitat. Further, we were able to start developing a network to gather more information about the 2 otter species present in this region. The current distribution of the Congo clawless otter (Gabon, Congo, Republic Democratic of Congo, south of Cameroon and RCA, north of Angola, and probably west of Uganda, Rwanda and Burundi was mapped from this information network as well as from the locality data of museum specimens. Data about its biology and current status were gathered from local sources and from field biologists working in Gabon and Congo. Threats seem mainly to be deforestation, hunting for bush meat and use for witchcraft materials. Four visits to the collections of natural history museums of London, New York, Paris, and Tervueren (Belgium, provided useful criteria to differentiate Congo clawless otter from Cape clawless otter (Aonyx. capensis. A possible sympatric overlap zone may occur between these species and might imply hybridization. However, this needs to be studied further.

  15. The Retarding Force on a Fan-Cart Reversing Direction

    Science.gov (United States)

    Aurora, Tarlok S.; Brunner, Bernard J.

    2011-01-01

    In introductory physics, students learn that an object tossed upward has a constant downward acceleration while going up, at the highest point and while falling down. To demonstrate this concept, a self-propelled fan cart system is used on a frictionless track. A quick push is given to the fan cart and it is allowed to move away on a track under…

  16. Female fans of men's football - a case study in Denmark

    DEFF Research Database (Denmark)

    Pfister, Gertrud Ursula; Lenneis, Verena; Mintert, Svenja-Maria

    2013-01-01

    to a 'man's world' and what are their roles in this 'male environment'? The statements of interviewees revealed that female fans have to cope with a measure of sexism, but that they can adopt the men's perspectives in order to be accepted as 'authentic fans'. Other women reacted on men's domination...

  17. Using Fan Fiction to Teach Critical Reading and Writing Skills

    Science.gov (United States)

    Kell, Tracey

    2009-01-01

    In this article, the author talks about fan fiction, which is defined by Jenkins (2008) as "original stories and novels which are set in the fictional universe of favorite television series, films, comics, games or other media properties." Fan fiction generally involves writing stories with a combination of established characters and established…

  18. Acoustic Measurements of an Uninstalled Spacecraft Cabin Ventilation Fan Prototype

    Science.gov (United States)

    Koch, L. Danielle; Brown, Clifford A.; Shook, Tony D.; Winkel, James; Kolacz, John S.; Podboy, Devin M.; Loew, Raymond A.; Mirecki, Julius H.

    2012-01-01

    Sound pressure measurements were recorded for a prototype of a spacecraft cabin ventilation fan in a test in the NASA Glenn Acoustical Testing Laboratory. The axial fan is approximately 0.089 m (3.50 in.) in diameter and 0.223 m (9.00 in.) long and has nine rotor blades and eleven stator vanes. At design point of 12,000 rpm, the fan was predicted to produce a flow rate of 0.709 cu m/s (150 cfm) and a total pressure rise of 925 Pa (3.72 in. of water) at 12,000 rpm. While the fan was designed to be part of a ducted atmospheric revitalization system, no attempt was made to throttle the flow or simulate the installed configuration during this test. The fan was operated at six speeds from 6,000 to 13,500 rpm. A 13-microphone traversing array was used to collect sound pressure measurements along two horizontal planes parallel to the flow direction, two vertical planes upstream of the fan inlet and two vertical planes downstream of the fan exhaust. Measurements indicate that sound at blade passing frequency harmonics contribute significantly to the overall audible noise produced by the fan at free delivery conditions.

  19. Procedure for Balancing an Air Distribution System with Decentralised Fans

    DEFF Research Database (Denmark)

    Gunner, Amalie; Hultmark, Göran; Vorre, Anders

    2015-01-01

    there is a potential for energy saving. In this study the calculated saving in the power consumption for the main fan was found to be 40%. The results also show that when dampers are replaced with decentralised fans with the same efficiency the overall power saving potential was 16%. In the study a mock-up...

  20. Amateur mythographies: Fan fiction and the myth of myth

    Directory of Open Access Journals (Sweden)

    Ika Willis

    2016-03-01

    Full Text Available This paper draws on classical scholarship on myth in order to critically examine three ways in which scholars and fans have articulated a relationship between fan fiction and myth. These are (1 the notion of fan fiction as a form of folk culture, reclaiming popular story from corporate ownership; (2 the notion of myth as counterhegemonic, often feminist, discourse; (3 the notion of myth as a commons of story and a universal story world. I argue that the first notion depends on an implicit primitivizing of fan fiction and myth, which draws ultimately on the work of Gottfried von Herder in the 18th century and limits our ability to produce historically and politically nuanced understandings of fan fiction. The second notion, which is visible in the work of Henry Jenkins and Constance Penley, is more helpful because of its attention to the politics of narration. However, it is the third model of myth, as a universal story world, where we find the richest crossover between fan fiction's creative power and contemporary classical scholarship on myth, especially in relation to Sarah Iles Johnston's analysis of hyperserial narrative. I demonstrate this through some close readings of fan fiction from the Greek and Roman Mythology fandom on Archive of Our Own. I conclude the paper by extending Johnston's arguments to show that fan-fictional hyperseriality, specifically, can be seen as mythic because it intervenes not only in the narrative worlds of its source materials but also in the social world of its telling.

  1. Gender constructions and negotiations of female football fans

    DEFF Research Database (Denmark)

    Lenneis, Verena; Pfister, Gertrud Ursula

    2015-01-01

    aims to give insight into gender constructions and negotiations of female football fans in the stands. Drawing on a social constructivist perspective to gender and Bourdieu's (1984) approaches to field, capital and habitus, we explored the experiences and opinions of female fans. The methods employed...

  2. 76 FR 50739 - Hung Ta Fan: Debarment Order

    Science.gov (United States)

    2011-08-16

    ... bases this order on a finding that Mr. Fan was convicted of a felony under Federal law for conduct... law). FDA's finding that debarment is appropriate is based on the felony conviction referenced herein... Thailand, when in fact he knew that the honey originated in China. Mr. Fan's actions allowed him to avoid...

  3. Simpler Variable-Speed Drive for Fan or Pump

    Science.gov (United States)

    Obler, H. D.

    1982-01-01

    Static pressure developed by a fan or pump is used directly to control its speed in a new drive unit. System is simpler and more economical than many other speed controllers, although it is less accurate and has a narrower speed range. However, since very accurate control is not usually required for fans and pumps, unit would work well in many applications.

  4. Facilitating Attuned Interactions: Using the FAN Approach to Family Engagement

    Science.gov (United States)

    Gilkerson, Linda

    2015-01-01

    Erikson Institute's Fussy Baby Network® (FBN) is a national model prevention program known for its approach to family engagement called the FAN (Gilkerson & Gray, 2014; Gilkerson et al., 2012). The FAN is both a conceptual framework and a practical tool to facilitate attunement in helping relationships and promote reflective practice. This…

  5. Wikipedia and participatory culture: Why fans edit [symposium

    Directory of Open Access Journals (Sweden)

    Paul Thomas

    2016-09-01

    Full Text Available Online, fans of popular culture media partake in participatory culture in various ways, such as writing fan fiction and scrutinizing media on message boards. Another way they do so is by editing relevant articles in the online encyclopedia Wikipedia. In fact, research has shown that Wikipedia articles skew heavily toward pop culture, suggesting that fans of pop culture are among the most enthusiastic of Wikipedia's editors. Of course, the question emerges: Why are pop culture fans in particular so interested in editing Wikipedia? Building on previous research, I argue that fans want to take part in the production of the media that they enjoy, that Wikipedia allows editors to create their own paratext (i.e., the Wikipedia article in relation to a main text (e.g., a movie, a television show, a book series, and that this paratext may be heavily used by the general public. Such usage is a form of implicit approval that affirms the editors' knowledge and encourages them to make more edits. Thus, Wikipedia validates the fan editor's work in a way that other outlets for participatory culture (e.g., fan fiction, fan art, songwriting cannot.

  6. Energy fan power consumption comparison of subway station HVAC system

    Institute of Scientific and Technical Information of China (English)

    JIANGYong; ZHUYingxin

    2003-01-01

    Subway thermal environment control system is a mass energy consumed system. The fan operation is the Key of energy saving. Some feasible fan operation modes are proposed and compared in this paper from the view of energy and operation cost saving. It is concluded that VAV is the optimal operation mode for metro system with highest energy saving.

  7. Nocturnal Fanning Suppresses Downy Mildew Epidemics in Sweet Basil.

    Directory of Open Access Journals (Sweden)

    Yigal Cohen

    Full Text Available Downy mildew is currently the most serious disease of sweet basil around the world. The oomycete causal agent Peronospora belbahrii requires ≥ 4h free leaf moisture for infection and ≥7.5h of water-saturated atmosphere (relative humidity RH≥95% at night for sporulation. We show here that continued nocturnal fanning (wind speed of 0.4-1.5 m/s from 8pm to 8am dramatically suppressed downy mildew development. In three experiments conducted during 2015, percent infected leaves in regular (non-fanned net-houses reached a mean of 89.9, 94.3 and 96.0% compared to1.2, 1.7 and 0.5% in adjacent fanned net-houses, respectively. Nocturnal fanning reduced the number of hours per night with RH≥95% thus shortened the dew periods below the threshold required for infection or sporulation. In experiments A, B and C, the number of nights with ≥4h of RH≥95% was 28, 10 and 17 in the non-fanned net-houses compared to 5, 0 and 5 in the fanned net-houses, respectively. In the third experiment leaf wetness sensors were installed. Dew formation was strongly suppressed in the fanned net-house as compared to the non-fanned net-house. Healthy potted plants became infected and sporulated a week later if placed one night in the non-fanned house whereas healthy plants placed during that night in the fanned house remained healthy. Infected potted basil plants sporulated heavily after one night of incubation in the non-fanned house whereas almost no sporulation occurred in similar plants incubated that night in the fanned house. The data suggest that nocturnal fanning is highly effective in suppressing downy mildew epidemics in sweet basil. Fanning prevented the within-canopy RH from reaching saturation, reduced dew deposition on the leaves, and hence prevented both infection and sporulation of P. belbahrii.

  8. Variable pitch fan system for NASA/Navy research and technology aircraft

    Science.gov (United States)

    Ryan, W. P.; Black, D. M.; Yates, A. F.

    1977-01-01

    Preliminary design of a shaft driven, variable-pitch lift fan and lift-cruise fan was conducted for a V/STOL Research and Technology Aircraft. The lift fan and lift-cruise fan employed a common rotor of 157.5 cm diameter, 1.18 pressure ratio variable-pitch fan designed to operate at a rotor-tip speed of 284 mps. Fan performance maps were prepared and detailed aerodynamic characteristics were established. Cost/weight/risk trade studies were conducted for the blade and fan case. Structural sizing was conducted for major components and weights determined for both the lift and lift-cruise fans.

  9. NORTHERN TANZANIA

    African Journals Online (AJOL)

    inertia, water balance, physiological strength, and susceptibility to predation between adults .... Judd PW and Rose FL 1977 Aspects of the thermal biology of the Texas tortoise ... pctrdolis lmheoeki) and their conservation in northern Tanzania.

  10. Costs and benefits of energy efficiency improvements in ceiling fans

    Energy Technology Data Exchange (ETDEWEB)

    Shah, Nihar; Sathaye, Nakul; Phadke, Amol; Letschert, Virginie [Lawrence Berkeley National Lab., CA (United States). Environmental Energy Technology Division

    2013-10-15

    Ceiling fans contribute significantly to residential electricity consumption, especially in developing countries with warm climates. The paper provides analysis of costs and benefits of several options to improve the efficiency of ceiling fans to assess the global potential for electricity savings and green house gas (GHG) emission reductions. Ceiling fan efficiency can be cost-effectively improved by at least 50% using commercially available technology. If these efficiency improvements are implemented in all ceiling fans sold by 2020, 70 terawatt hours per year could be saved and 25 million metric tons of carbon dioxide equivalent (CO2-e) emissions per year could be avoided, globally. We assess how policies and programs such as standards, labels, and financial incentives can be used to accelerate the adoption of efficient ceiling fans in order to realize potential savings.

  11. Portable Fan Assembly for the International Space Station

    Science.gov (United States)

    Jenkins, Arthur A.; Roman, Monsi C.

    1999-01-01

    NASA/ Marshall Space Flight Center (NASA/MSFC) is responsible for the design and fabrication of a Portable Fan Assembly (PFA) for the International Space Station (ISS). The PFA will be used to enhance ventilation inside the ISS modules as needed for crew comfort and for rack rotation. The PFA consists of the fan on-orbit replaceable unit (ORU) and two noise suppression packages (silencers). The fan ORU will have a mechanical interface with the Seat Track Equipment Anchor Assembly, in addition to the power supply module which includes a DC-DC converter, on/standby switch, speed control, power cable and connector. This paper provides a brief development history, including the criteria used for the fan, and a detailed description of the PFA operational configurations. Space Station requirements as well as fan performance characteristics are also discussed.

  12. Sediment velocities from sonobuoys: Bengal Fan, Sunda Trench, Andaman Basin, and Nicobar Fan

    Energy Technology Data Exchange (ETDEWEB)

    Hamilton, E.L.; Bachman, R.T.; Curray, J.R.; Moore, D.G.

    1977-07-10

    New measurements of interval compressional wave velocities were made in the first sediment layer using the sonobuoy technique during two expeditions in the Bay of Bengal, in the Andaman Sea, and over the Nicobar Fan and Sunda Trench. Sediment interval velocities from these areas were added to those previously reported, and revised diagrams and regression equations of instantaneous and mean velocity versus one-way travel time are furnished for four areas of the Bengal Fan, and for the Anadman Basin, Nicobar Fan, Sunda Trench. The velocity gradients directly below the sea floor were used to separate the Bengal Fan into four geoacoustic provinces. In the north and west the velocity gradients are 0.86 and 1.28 s/sup -1/, respectively, whereas in the central part of the fan the gradient is 1.87 s/sup -1/. These variations indicate lesser increases of velocity with depth in the sea floor in the north and west, and they are probably due to more rapid deposition, less consolidation, and less lithification near the riverine source areas of the sediments. The near-surface velocity gradients in the other areas are the Andaman Basin, 1.53 s/sup -1/, the Nicobar Fan 1.63 s/sup -1/, and the Sunda Trench, 1.41 s/sup -1/. The linear velocity gradients (from the sediment surface to a given travel time) in 17 areas of the Indian Ocean, Pacific area, Atlantic Ocean, and Gulf of Mexico were averaged at each 0.1 s from 0 to 0.5 s of one-way travel time. These averaged gradients ranged from 1.32 s/sup -1/ at t=0 to 0.76 s/sup -1/ at t=0.5 s. The regression equation for the velocity gradients a, in s/sup -1/, as a function of one-way travel time t, in seconds, is a=1.316-1.117t (for use from t=0 to 0.5 s). These average velocity gradients can be used with sediment surface velocities and one-way travel times (measured from reflection records) to compute sediment layer thickness in areas of turbidites lacking interval velocity measurements in the first sediment layer.

  13. Development of a Fan for Future Space Suit Applications

    Science.gov (United States)

    Paul. Heather L.; Converse, David; Dionne, Steven; Moser, Jeff

    2010-01-01

    NASA's next generation space suit system will place new demands on the fan used to circulate breathing gas through the ventilation loop of the portable life support system. Long duration missions with frequent extravehicular activities (EVAs), the requirement for significant increases in reliability and durability, and a mission profile that imposes strict limits on weight, volume and power create the basis for a set of requirements that demand more performance than is available from existing fan designs. This paper describes the development of a new fan to meet these needs. A centrifugal fan was designed with a normal operating speed of approximately 39,400 rpm to meet the ventilation flow requirements while also meeting the aggressive minimal packaging, weight and power requirements. The prototype fan also operates at 56,000 rpm to satisfy a second operating condition associated with a single fan providing ventilation flow to two spacesuits connected in series. This fan incorporates a novel nonmetallic "can" to keep the oxygen flow separate from the motor electronics, thus eliminating ignition potential. The nonmetallic can enables a small package size and low power consumption. To keep cost and schedule within project bounds a commercial motor controller was used. The fan design has been detailed and implemented using materials and approaches selected to address anticipated mission needs. Test data is presented to show how this fan performs relative to anticipated ventilation requirements for the EVA portable life support system. Additionally, data is presented to show tolerance to anticipated environmental factors such as acoustics, shock, and vibration. Recommendations for forward work to progress the technology readiness level and prepare the fan for the next EVA space suit system are also discussed.

  14. Alluvial Fan Morphology, distribution and formation on Titan

    Science.gov (United States)

    Birch, S. P. D.; Hayes, A. G.; Howard, A. D.; Moore, J. M.; Radebaugh, J.

    2016-05-01

    Titan is a hydrologically active world, with dozens of alluvial fans that are evidence of sediment transport from high to low elevations. However, the distribution and requirements for the formation of fans on Titan are not well understood. We performed the first global survey of alluvial fans on Titan using Cassini Synthetic Aperture Radar (SAR) data, which cover 61% of Titan's surface. We identified 82 fans with areas ranging from 28 km2 to 27,000 km2. A significant fraction (∼60%) of the fans are restricted to latitudes of ±50-80°, suggesting that fluvial sediment transport may have been concentrated in the near-polar terrains in the geologically recent past. The density of fans is also found to be correlated with the latitudes predicted to have the highest precipitation rates by Titan Global Circulation Models. In equatorial regions, observable fans are not generally found in proximity to dune fields. Such observations suggest that sediment transport in these areas is dominated by aeolian transport mechanisms, though with some degree of recent equatorial fluvial activity. The fan area-drainage area relationship on Titan is more similar to that on Earth than on Mars, suggesting that the fans on Titan are smaller than what may be expected, and that the transport of bedload sediment is limited. We hypothesize that this has led to the development of a coarse gravel-lag deposit over much of Titan's surface. Such a model explains both the morphology of the fans and their latitudinal concentration, yielding insight into the sediment transport regimes that operate across Titan today.

  15. Variation Of amp94813C And Soil Organic Carbon Dynamics In The Savannah Of Plateau Bateke Congo Bassin

    Directory of Open Access Journals (Sweden)

    Ifo suspense Averti

    2015-08-01

    Full Text Available In Republic of Congo forests occupy 64.6 of the territory. They spread from north to south over nearly 22106 ha distributed in three major zones the forest of the Northern Congo 68 the forest of Chaillu 16 and the forest of Mayombe 7. The remaining 9 are mosaic forests and savannah mostly gallery and forest clump HF forests like in the Iboubikro site 311S 1528E. Currently characterized by a positive dynamics for at least five or six centuries these natural forests could play an important role in the mitigation of CO2 in the atmosphere. The objective of this work i-quantifying carbon stock in forests and savannah ii following deep inputs of organic matter originated from savannah and forest. The results obtained showed that the total carbon up to one meter is more important in the gallery and secondary forest than under the savannah. We obtained up to one meter 6.4 kg.m-2 in the GF 6.2 kg.m-2 in SF and 4.6 kg.m-2 in the savannah. The three means of total C are differ from one site to another p0.0001. A Study of the variation of amp94813C with profile depth showed that in the forest the amp94813C values were close to those of C3 -26 amp94813C decrease in depth until -19 in the deepest at -100 cm. Under savannah the amp94813C values are close to those of C4 vegetation -13.6 . In all the profile under savannah we observed that the amp94813C values are constant. We concluded that there is a clear mixture between old organic matter from savannah and the new organic matter from trees. The result suggests a net effect of the growing of forest on the old savannah vegetation due to climate change in this area.

  16. Life, death and revival of debris-flow fans on Earth and Mars : fan dynamics and climatic inferences

    NARCIS (Netherlands)

    de Haas, T.

    2016-01-01

    Alluvial fans are ubiquitous landforms in high-relief regions on Earth and Mars. They have a semi-conical shape and are located at the transition between highlands and adjacent basins. Alluvial fans can form by a range of processes including debris flows, which are water-laden masses of soil and

  17. Life, death and revival of debris-flow fans on Earth and Mars : fan dynamics and climatic inferences

    NARCIS (Netherlands)

    de Haas, T.

    2016-01-01

    Alluvial fans are ubiquitous landforms in high-relief regions on Earth and Mars. They have a semi-conical shape and are located at the transition between highlands and adjacent basins. Alluvial fans can form by a range of processes including debris flows, which are water-laden masses of soil and roc

  18. Life, death and revival of debris-flow fans on Earth and Mars : fan dynamics and climatic inferences

    NARCIS (Netherlands)

    de Haas, T.

    2016-01-01

    Alluvial fans are ubiquitous landforms in high-relief regions on Earth and Mars. They have a semi-conical shape and are located at the transition between highlands and adjacent basins. Alluvial fans can form by a range of processes including debris flows, which are water-laden masses of soil and roc

  19. Aerodynamic Modelling and Optimization of Axial Fans

    DEFF Research Database (Denmark)

    Sørensen, Dan Nørtoft

    A numerically efficient mathematical model for the aerodynamics oflow speed axial fans of the arbitrary vortex flow type has been developed.The model is based on a blade-element principle, whereby therotor is divided into a number of annular streamtubes.For each of these streamtubes relations...... for velocity, pressure andradial position are derived from the conservationlaws for mass, tangential momentum and energy.The resulting system of equations is non-linear and, dueto mass conservation and pressure equilibrium far downstream of the rotor,strongly coupled.The equations are solved using the Newton...... distributionsof pitch angle and chord length have been chosen as independent variablesin the optimizations.Besides restricting the geometry of the rotor,constraints have been added to ensure a required pressure rise as well asnon-stalled flow conditions.Optimizations have been performed tomaximize the mean value...

  20. A generalization of Ky Fan's inequality

    Directory of Open Access Journals (Sweden)

    Peng Gao

    2001-01-01

    defined by f(x,y=0 and 0Fan's inequality. We also present some results on the comparison of Pn,sα(y−Pn,rα(y and Pn,sα(x−Pn,rα(x for s≥r, α∈ℝ.

  1. Failure analysis of air fan blades

    Institute of Scientific and Technical Information of China (English)

    WANG Yan-qing; JI Zhe; CUI Yong-li; CUI Chun-zhi; SUN Zhi

    2008-01-01

    The failure of all 12 blades of an air fan was investigated by metallurgical and mechanical experiments and an examina-tion of the fracture surface. The experimental results show that the cast aluminium-silicon alloy without any modification had a number of material defects, such as coarse grains, a loose structure, a large number of shrinkage holes, a long and thin bold-pin shaped silicon-phase, poor material strength and serious brittleness. In addition, installed on the spindle without elastic conjunction,blade No. 10 vibrated and inevitably.spun off due to the large centrifugal force. Therefore, blade No. 10 first cracked at the locking handle, then broke at the root, which caused all the other 11 blades to be broken by the crack of blade No.10.

  2. Soap operas and the history of fan discussion

    Directory of Open Access Journals (Sweden)

    Sam Ford

    2008-09-01

    Full Text Available For decades, fans of U.S. soap operas have formed social networks surrounding their shows, and they did so even before the concept entered the vernacular. Soap fans, who started on a geographically local scale and built their communities through grassroots efforts, have found a variety of venues to connect with one another over the past several decades. This study looks at the pre-Internet development of these social networks to show how that trajectory relates to the current online community of soap opera fans. Although several scholars have studied soap opera fandom, few have taken an historical approach at understanding the trajectory of soap fandom, a view especially necessary in an era where online social networks are at the center of audience studies and where cornerstone U.S. soap operas are struggling to retain relevance and audience. To fill this gap, I argue that understanding fan networks today requires looking back to previous methods of fan networking. Soaps' longevity (the youngest U.S. soap is more than 20 years old and frequency (all U.S. daytime soaps are daily make them crucial texts in demonstrating how the roots of fan social networks in a pre-Internet era helped shape that fandom's transition onto the Internet, and they also illustrate the continued evolution of these networks as fans move online.

  3. Experimental determination of tunnel ventilation axial ducted fan performance

    Directory of Open Access Journals (Sweden)

    Šekularac Milan B.

    2016-01-01

    Full Text Available To investigate traffic tunnel ventilation flows, a scaled model of a traffic tunnel with longitudinal ventilation system based on ducted fans is used. Flows in tunnels are influenced by tunnel geometry, fan characteristics, ventilation operation scenario, vehicle traffic, atmospheric factors, etc. To analyze flow fields of tunnels in detail, knowledge of tunnel jet-fan properties and turbulent flow characteristics at the fan exit are required, and can be used as input data for CFD boundary conditions of tunnel flow computation. For this purpose experimental measurements were done using the hot wire anemometry technique. The obtained results, trough ensemble-averaged and time averaged profiles of all velocity components, turbulence intensity, turbulent kinetic energy, integral flow length scales, available Reynolds stresses, Turbulent kinetic energy production rates and the fan thrust performance, are presented. These data allow us to analyze in more detail the influence of fan flow on energy and pollutant removal efficiencies of the tunnel ventilation and to evaluate accuracy of CFD studies on fan improvements.

  4. Reactive control of subsonic axial fan noise in a duct.

    Science.gov (United States)

    Liu, Y; Choy, Y S; Huang, L; Cheng, L

    2014-10-01

    Suppressing the ducted fan noise at low frequencies without varying the flow capacity is still a technical challenge. This study examines a conceived device consisting of two tensioned membranes backed with cavities housing the axial fan for suppression of the sound radiation from the axial fan directly. The noise suppression is achieved by destructive interference between the sound fields from the axial fan of a dipole nature and sound radiation from the membrane via vibroacoustics coupling. A two-dimensional model with the flow effect is presented which allows the performance of the device to be explored analytically. The air flow influences the symmetrical behavior and excites the odd in vacuo mode response of the membrane due to kinematic coupling. Such an asymmetrical effect can be compromised with off-center alignment of the axial fan. Tension plays an important role to sustain the performance to revoke the deformation of the membrane during the axial fan operation. With the design of four appropriately tensioned membranes covered by a cylindrical cavity, the first and second blade passage frequencies of the axial fan can be reduced by at least 20 dB. The satisfactory agreement between experiment and theory demonstrates that its feasibility is practical.

  5. Understanding Himalayan erosion and the significance of the Nicobar Fan

    Science.gov (United States)

    McNeill, Lisa C.; Dugan, Brandon; Backman, Jan; Pickering, Kevin T.; Pouderoux, Hugo F. A.; Henstock, Timothy J.; Petronotis, Katerina E.; Carter, Andrew; Chemale, Farid; Milliken, Kitty L.; Kutterolf, Steffen; Mukoyoshi, Hideki; Chen, Wenhuang; Kachovich, Sarah; Mitchison, Freya L.; Bourlange, Sylvain; Colson, Tobias A.; Frederik, Marina C. G.; Guèrin, Gilles; Hamahashi, Mari; House, Brian M.; Hüpers, Andre; Jeppson, Tamara N.; Kenigsberg, Abby R.; Kuranaga, Mebae; Nair, Nisha; Owari, Satoko; Shan, Yehua; Song, Insun; Torres, Marta E.; Vannucchi, Paola; Vrolijk, Peter J.; Yang, Tao; Zhao, Xixi; Thomas, Ellen

    2017-10-01

    A holistic view of the Bengal-Nicobar Fan system requires sampling the full sedimentary section of the Nicobar Fan, which was achieved for the first time by International Ocean Discovery Program (IODP) Expedition 362 west of North Sumatra. We identified a distinct rise in sediment accumulation rate (SAR) beginning ∼9.5 Ma and reaching 250-350 m/Myr in the 9.5-2 Ma interval, which equal or far exceed rates on the Bengal Fan at similar latitudes. This marked rise in SAR and a constant Himalayan-derived provenance necessitates a major restructuring of sediment routing in the Bengal-Nicobar submarine fan. This coincides with the inversion of the Eastern Himalayan Shillong Plateau and encroachment of the west-propagating Indo-Burmese wedge, which reduced continental accommodation space and increased sediment supply directly to the fan. Our results challenge a commonly held view that changes in sediment flux seen in the Bengal-Nicobar submarine fan were caused by discrete tectonic or climatic events acting on the Himalayan-Tibetan Plateau. Instead, an interplay of tectonic and climatic processes caused the fan system to develop by punctuated changes rather than gradual progradation.

  6. Fans of Columbine shooters Eric Harris and Dylan Klebold

    Directory of Open Access Journals (Sweden)

    Andrew Ryan Rico

    2015-09-01

    Full Text Available On April 20, 1999, Eric Harris and Dylan Klebold murdered 12 students and one teacher at Columbine High School in Littleton, Colorado, in what was then the deadliest school shooting in American history. Despite causing a national panic and serving as a flash point for larger narratives on bullying, gun control, and media violence, both boys have gained active online fans. These fandoms dedicated to the Columbine shooters are widely referred to as dark examples of Internet communities, while the fans are also frequently denigrated as unstable and violent outcasts. Such dark online fandoms are yet to permeate mainstream culture or to challenge the preexisting perception of these communities as breeding grounds for the next wave of school shooters. While studies have covered the types of fans and their myriad interests, the field remains focused on more conventional examples of fan communities. In an effort to challenge and expand the object of focus when we study fandom, this qualitative study examines Columbine fans and their activity in order to understand the dominant motives they appear to have for engaging with and around such controversial figures and then concludes by exploring how this community might help us reflect more broadly on our concept of fandom. Redeeming these fans as part of diverse and complex communities of social relevance can demonstrate how even a dark fandom such as that of these Columbine shooters provides valuable cultural insights and benefits the field of fan studies.

  7. rett produc Congo ted cas ced in to: Nsam ssava two tra m

    African Journals Online (AJOL)

    sunny

    d beverages zation of con .... Among the local beverages consumed in Congo is palm wine. ... fermentation is alcoholic) (Brassir, 1962; Faparusi and. Brassir, 1972 ..... Asian Symposium on non-salted soybean fermentation, Tsukuba,. Japan ...

  8. The Adf Insurgency Network in the Eastern Democratic Republic of the Congo: Spillover Effects Into Tanzania

    Science.gov (United States)

    2014-06-01

    30 4. Peace Deal of 2003 ..............................................................................30 5. Goma Peace Agreement of 2008...31 6. Goma Peace Accord of 2009...of two factions: RCD- Goma backed by Rwanda, 133 Autesserre, The Trouble with the Congo, 48. 134 The

  9. One step effective removal of Congo Red in chitosan nanoparticles by encapsulation

    Science.gov (United States)

    Alver, Erol; Bulut, Mehmet; Metin, Ayşegül Ülkü; Çiftçi, Hakan

    2017-01-01

    Chitosan nanoparticles (CNPs) were prepared with ionotropic gelation between chitosan and tripolyphosphate for the removal of Congo Red. The production of chitosan nanoparticles and the dye removal process was carried out in one-step. The removal efficiency of Congo Red by encapsulation within chitosan from the aqueous solution and its storage stability are examined at different pH values. The influence of some parameters such as the initial dye concentration, pH value of the dye solution, electrolyte concentration, tripolyphosphate concentration, mixing time and speed on the encapsulation is examined. Congo Red removal efficiency and encapsulation capacity of chitosan nanoparticles were determined as above 98% and 5107 mg Congo Red/g chitosan, respectively.

  10. Crimean-Congo hemorrhagic fever infections reported by ProMED

    Directory of Open Access Journals (Sweden)

    Yavuz Ince

    2014-09-01

    Conclusions: Case reporting systems such as ProMED are useful to gather information and synthesize knowledge on the emerging infections. Although certain areas need to be improved, ProMED provided good information about Crimean-Congo hemorrhagic fever.

  11. Effective community-based protection programming: lessons from the Democratic Republic of Congo

    Directory of Open Access Journals (Sweden)

    Richard Nunn

    2016-10-01

    Full Text Available Oxfam’s work with local communities in eastern Democratic Republic of Congo has prompted the organisation to develop guidance for themselves and for others working in similar situations.

  12. Biogeochemical processes in the northern Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Gaye-Haake, B.; Guptha, M.V.S.; Murty, V.S.N.; Ittekkot, V.

    of dustfromtheArabianPeninsula,SomaliandThar Deep-Sea Research II 52 Editorial Biogeochemical Processes in This DSR II volume presents selected papers froman‘‘InternationalWorkshoponbiogeochem- ical processes in the northern Indian Ocean’’ coorganized...) the southern fan area via active deep-sea channels. The Of the 16 papers contained in this volume 11 erosion and convective overturn. Summer mon- desertstotheArabianSea.ThepaperbySchu¨ssler ARTICLE IN PRESS deal with the Arabian Sea, 2 with the Bay of Bengal...

  13. Adsorption of Congo Red onto Lignocellulose/Montmorillonite Nanocomposite

    Institute of Scientific and Technical Information of China (English)

    ZHAO Yahong; XUE Zhenhua; WANG Ximing; WANG Li; WANG Aiqin

    2012-01-01

    Lignocellulose/montmorillonite (LNC/MMT) nanocomposites were prepared and characterized by FTIR and XRD.The adsorption of congo red (CR) on LNC/MMT nanocomposite was studied in detail.The effects of contact temperature,pH value of the dye solutions,contact time and concentration of dye solutions on the adsorption capacities of lignocellulose (LNC),montmorillonite (MMT) and the nanocomposite were investigated.The adsorption kinetics and isotherms and adsorption thermodynamics of the nanocomposite for CR were also studied.The results show that the adsorption capacity of LNC/MMT nanocomosite is higher than that of LNC and MMT.All the adsorption processes fit very well with the pseudo-second-order and the Langmuir equation.From thermodynamic studies,it is seen that the adsorption is spontaneous and endothermic.

  14. The bushmeat market in Kisangani, Democratic Republic of Congo

    DEFF Research Database (Denmark)

    van Vliet, Nathalie; Nebesse, Casimir; Gambalemoke, Sylvestre

    2012-01-01

    Given the important contribution of urban consumption in bushmeat trade, information on bushmeat sales in urban markets can provide valuable insights for understanding the dynamics of this trade and its implications for conservation and food security. We monitored bushmeat traded in the market...... bushmeat was one of the cheapest sources of protein available year-round, together with caterpillars, which were only available during the rainy season, and pork. Prices of other domestic meat were significantly higher. This study identified an increase in the market of highly threatened species...... of Kisangani (the provincial capital of the Province Orientale in the Democratic Republic of Congo) and compared data collected in surveys in 2002 and 2008–2009. In both periods more than two-thirds of the carcasses sold were of rodents and ungulates. From 2002 to 2008–2009 the number of carcasses increased...

  15. Autochthonous Crimean-Congo Hemorrhagic Fever in Spain.

    Science.gov (United States)

    Negredo, Anabel; de la Calle-Prieto, Fernando; Palencia-Herrejón, Eduardo; Mora-Rillo, Marta; Astray-Mochales, Jenaro; Sánchez-Seco, María P; Bermejo Lopez, Esther; Menárguez, Javier; Fernández-Cruz, Ana; Sánchez-Artola, Beatriz; Keough-Delgado, Elena; Ramírez de Arellano, Eva; Lasala, Fátima; Milla, Jakob; Fraile, Jose L; Ordobás Gavín, Maria; Martinez de la Gándara, Amalia; López Perez, Lorenzo; Diaz-Diaz, Domingo; López-García, M Aurora; Delgado-Jimenez, Pilar; Martín-Quirós, Alejandro; Trigo, Elena; Figueira, Juan C; Manzanares, Jesús; Rodriguez-Baena, Elena; Garcia-Comas, Luis; Rodríguez-Fraga, Olaia; García-Arenzana, Nicolás; Fernández-Díaz, Maria V; Cornejo, Victor M; Emmerich, Petra; Schmidt-Chanasit, Jonas; Arribas, Jose R

    2017-07-13

    Crimean-Congo hemorrhagic fever (CCHF) is a widely distributed, viral, tickborne disease. In Europe, cases have been reported only in the southeastern part of the continent. We report two autochthonous cases in Spain. The index patient acquired the disease through a tick bite in the province of Ávila - 300 km away from the province of Cáceres, where viral RNA from ticks was amplified in 2010. The second patient was a nurse who became infected while caring for the index patient. Both were infected with the African 3 lineage of this virus. (Funded by Red de Investigación Cooperativa en Enfermedades Tropicales [RICET] and Efficient Response to Highly Dangerous and Emerging Pathogens at EU [European Union] Level [EMERGE].).

  16. A case of brucellosis mimicking Crimean-Congo hemorrhagic fever.

    Science.gov (United States)

    Metin, Ozge; Teke, Turkan A; Gayretli Aydin, Zeynep G; Kaman, Ayse; Oz, Fatma N; Bayhan, Gulsum I; Tanir, Gonul

    2015-01-01

    Brucellosis is a zoonotic disease caused by Brucella spp. that is transmitted to humans by the ingestion of unpasteurized milk and other dairy products from infected animals or through close contact with secretions. Crimean-Congo hemorrhagic fever (CCHF) is a tick-borne disease caused by a virus that is transmitted to humans by ixoid tick bites, contact with blood and tissue of infected animals or contact with infected humans. The symptoms of brucellosis are non-specific; it can mimic other diseases. In this paper, we present a case of brucellosis that was initially evaluated as CCHF. We emphasize that brucellosis should be considered in the differential diagnosis of CCHF, especially in endemic countries.

  17. Ebola Virus Disease, Democratic Republic of the Congo, 2014

    Science.gov (United States)

    Nanclares, Carolina; Kapetshi, Jimmy; Lionetto, Fanshen; de la Rosa, Olimpia; Tamfun, Jean-Jacques Muyembe; Alia, Miriam; Kobinger, Gary

    2016-01-01

    During July–November 2014, the Democratic Republic of the Congo underwent its seventh Ebola virus disease (EVD) outbreak. The etiologic agent was Zaire Ebola virus; 66 cases were reported (overall case-fatality rate 74.2%). Through a retrospective observational study of confirmed EVD in 25 patients admitted to either of 2 Ebola treatment centers, we described clinical features and investigated correlates associated with death. Clinical features were mainly generic. At admission, 76% of patients had >1 gastrointestinal symptom and 28% >1 hemorrhagic symptom. The case-fatality rate in this group was 48% and was higher for female patients (67%). Cox regression analysis correlated death with initial low cycle threshold, indicating high viral load. Cycle threshold was a robust predictor of death, as were fever, hiccups, diarrhea, dyspnea, dehydration, disorientation, hematemesis, bloody feces during hospitalization, and anorexia in recent medical history. Differences from other outbreaks could suggest guidance for optimizing clinical management and disease control. PMID:27533284

  18. Spatial analysis of Crimean Congo hemorrhagic fever in Iran.

    Science.gov (United States)

    Mostafavi, Ehsan; Haghdoost, AliAkbar; Khakifirouz, Sahar; Chinikar, Sadegh

    2013-12-01

    Crimean Congo hemorrhagic fever (CCHF) is a viral zoonotic disease. During 1999-2011, 871 human cases of CCHF were diagnosed in Iran. A history of serologic conversion for CCHF virus was seen in 58.7% of 2,447 sheep samples, 25.0% of 1,091 cattle samples and 24.8% of 987 goat samples from different parts of Iran. Spatial analysis showed that the main foci of this disease in humans during these years were in eastern Iran (P Iran. Two livestock foci were detected in the northeastern northwestern Iran. On the basis of the results of this study, infection likely entered Iran from eastern and western neighboring countries.

  19. Use of booster fans in underground coal mining to advantage

    Institute of Scientific and Technical Information of China (English)

    Habibi A; Gillies A D S

    2011-01-01

    A booster fan is an underground main fan which is installed in series with a main surface fan and used to boost the air pressure of the ventilation to overcome mine resistance.Currently booster fans are used in several major coal mining countries including the United Kingdom,Australia,Poland and China.In the United States booster fans are prohibited in coal mines although they are used in several metal and non-metal mines.A study has been undertaken to examine alternatives for ventilating an underground room and pillar coal mine system.A feasibility study of a hypothetical situation has shown that current ventilation facilities are incapable of fulfilling mine air requirements in the future due to increased seam methane levels.A current ventilation network model has been prepared and projected to a mine five years plan.“Ventsim visual” software simulations of different possible ventilation options have been conducted in which varying methane levels are found at working faces.The software can also undertake financial simulations and project present value total costs for the options under study.Several scenarios for improving the ventilation situation such as improving main surface fans,adding intake shafts,adding exhaust shafts and utilizing booster fans have been examined.After taking into account the total capital and operating costs for the five years mine plan the booster fan scenarios are recommended as being the best alternatives for further serious consideration by the mine.The optimum option is a properly sized and installed booster fan system that can be used to create safe work conditions,maintain adequate air quantity with lowest cost,generate a reduction in energy consumption and decrease mine system air leakage.

  20. Triassic rift-related sedimentary basins in northern Chile (24° 29°S)

    Science.gov (United States)

    Suarez, M.; Bell, C. M.

    1992-10-01

    Triassic rocks in northern Chile (latitude 24°-29°S) include marine and continental rift-related sedimentary deposits, associated with basaltic, andesitic, and silicic volcanic rocks. Five main successions include the deposits of two marine basins (Profeta and San Félix) separated by three continental basins (Cifuncho, La Ternera, and La Coipa). The marine strata include turbidites and debris flow deposits interpreted as coarse-grained fan-delta sediments. The continental sediments include lacustrine fan delta, open lake, braided river, alluvial fan, and sabkha deposits. The widespread fan-delta systems (both marine and lacustrine), together with abrupt lateral and vertical facies discontinuities and large-scale depositional cycles, are indicative of rift-controlled sedimentation. The associated magmatic activity indicates that this rifting was the product of subduction-related extension or strike-slip movement on the active plate margin. Triassic rifting was followed in Late Triassic to Early Jurassic times by widespread thermotectonic subsidence.

  1. Simulated hydrologic response to projected changes in precipitation and temperature in the Congo River basin

    Directory of Open Access Journals (Sweden)

    N. Aloysius

    2017-08-01

    Full Text Available Despite their global significance, the impacts of climate change on water resources and associated ecosystem services in the Congo River basin (CRB have been understudied. Of particular need for decision makers is the availability of spatial and temporal variability of runoff projections. Here, with the aid of a spatially explicit hydrological model forced with precipitation and temperature projections from 25 global climate models (GCMs under two greenhouse gas emission scenarios, we explore the variability in modeled runoff in the near future (2016–2035 and mid-century (2046–2065. We find that total runoff from the CRB is projected to increase by 5 % [−9 %; 20 %] (mean – min and max – across model ensembles over the next two decades and by 7 % [−12 %; 24 %] by mid-century. Projected changes in runoff from subwatersheds distributed within the CRB vary in magnitude and sign. Over the equatorial region and in parts of northern and southwestern CRB, most models project an overall increase in precipitation and, subsequently, runoff. A simulated decrease in precipitation leads to a decline in runoff from headwater regions located in the northeastern and southeastern CRB. Climate model selection plays an important role in future projections for both magnitude and direction of change. The multimodel ensemble approach reveals that precipitation and runoff changes under business-as-usual and avoided greenhouse gas emission scenarios (RCP8.5 vs. RCP4.5 are relatively similar in the near term but deviate in the midterm, which underscores the need for rapid action on climate change adaptation. Our assessment demonstrates the need to include uncertainties in climate model and emission scenario selection during decision-making processes related to climate change mitigation and adaptation.

  2. Crimean-Congo hemorrhagic fever virus activates endothelial cells.

    Science.gov (United States)

    Connolly-Andersen, Anne-Marie; Moll, Guido; Andersson, Cecilia; Akerström, Sara; Karlberg, Helen; Douagi, Iyadh; Mirazimi, Ali

    2011-08-01

    Crimean-Congo hemorrhagic fever virus (CCHFV) causes viral hemorrhagic fever with high case-fatality rates and is geographically widely distributed. Due to the requirement for a biosafety level 4 (BSL-4) laboratory and the lack of an animal model, knowledge of the viral pathogenesis is limited. Crimean-Congo hemorrhagic fever (CCHF) is characterized by hemorrhage and vascular permeability, indicating the involvement of endothelial cells (ECs). The interplay between ECs and CCHFV is therefore important for understanding the pathogenesis of CCHF. In a previous study, we found that CCHFV-infected monocyte-derived dendritic cells (moDCs) activated ECs; however, the direct effect of CCHFV on ECs was not investigated. Here, we report that ECs are activated upon infection, as demonstrated by upregulation of mRNA levels for E-selectin, vascular cell adhesion molecule 1 (VCAM1), and intercellular adhesion molecule 1 (ICAM1). Protein levels and cell surface expression of ICAM1 responded in a dose-dependent manner to increasing CCHFV titers with concomitant increase in leukocyte adhesion. Furthermore, we examined vascular endothelial (VE) cadherin in CCHFV-infected ECs by different approaches. Infected ECs released higher levels of interleukin 6 (IL-6) and IL-8; however, stimulation of resting ECs with supernatants derived from infected ECs did not result in increased ICAM1 expression. Interestingly, the moDC-mediated activation of ECs was abrogated by addition of neutralizing tumor necrosis factor alpha (TNF-α) antibody to moDC supernatants, thereby identifying this soluble mediator as the key cytokine causing EC activation. We conclude that CCHFV can exert both direct and indirect effects on ECs.

  3. Lightning climatology in the Congo Basin: detailed analysis

    Science.gov (United States)

    Soula, Serge; Kigotsi, Jean; Georgis, Jean-François; Barthe, Christelle

    2016-04-01

    The lightning climatology of the Congo Basin including several countries of Central Africa is analyzed in detail for the first time. It is based on World Wide Lightning Location Network (WWLLN) data for the period from 2005 to 2013. A comparison of these data with the Lightning Imaging Sensor (LIS) data for the same period shows the WWLLN detection efficiency (DE) in the region increases from about 1.70 % in the beginning of the period to 5.90 % in 2013, relative to LIS data, but not uniformly over the whole 2750 km × 2750 km area. Both the annual flash density and the number of stormy days show sharp maximum values localized in eastern of Democratic Republic of Congo (DRC) and west of Kivu Lake, regardless of the reference year and the period of the year. These maxima reach 12.86 fl km-2 and 189 days, respectively, in 2013, and correspond with a very active region located at the rear of the Virunga mountain range characterised with summits that can reach 3000 m. The presence of this range plays a role in the thunderstorm development along the year. The estimation of this local maximum of the lightning density by taking into account the DE, leads to a value consistent with that of the global climatology by Christian et al. (2003) and other authors. Thus, a mean maximum value of about 157 fl km-2 y-1 is found for the annual lightning density. The zonal distribution of the lightning flashes exhibits a maximum between 1°S and 2°S and about 56 % of the flashes located below the equator in the 10°S - 10°N interval. The diurnal evolution of the flash rate has a maximum between 1400 and 1700 UTC, according to the reference year, in agreement with previous works in other regions of the world.

  4. FOOD CONSUMPTION AND PREFERENCES OF THE BONGANDO PEOPLE IN THE DEMOCRATIC REPUBLIC OF THE CONGO

    OpenAIRE

    YAMAGUCHI, Ryota

    2015-01-01

    People living in the Congo basin forest have developed a variety of ways to use natural resources. Thus, the increase in conservation projects must be accompanied by efforts to clarify the livelihood-related conditions of local people. This paper provided a detailed investigation of the utilization of natural resources by the Bongando people living in the great ape habitat of the Democratic Republic of the Congo (DRC). Specifically, the paper examined food acquisition and consumption based on...

  5. Dragon Operations: Hostage Rescues in the Congo, 1964-1965 (Leavenworth Papers, Number 14)

    Science.gov (United States)

    1988-01-01

    Carper , they ran into a firefight. Carper , another missionary from Kilometer 8, was anxious to get to the mission, but· their Congolese driver refused...and Barbara A. Wilson, "The Congo (Republic of the Congo-Leopoldville) Since January 1964," in Research Notes on Insurgency Potential in Africa...Vandewalle interview; and Laurent interview. 65. Rattan. " Bukavu to Stanleyville," 67-68; Rattan interview; Delbert Carper , interview with Reader’s

  6. Republic of Congo; Joint Advisory Note on the Poverty Reduction Strategy Paper: Annual Progress Report

    OpenAIRE

    International Monetary Fund

    2010-01-01

    This Joint Staff Advisory Note reviews the first annual progress report (APR) on implementation of the Poverty Reduction Strategy (PRS) in the Republic of Congo. The adoption of Congo’s first full Poverty Reduction Strategy Paper was an important step toward consolidating macroeconomic stability and improved political and economic governance. The APR takes stock of the first year of PRS monitoring and implementation, and provides an update on the poverty diagnosis, and elaborates on the cen...

  7. Female fans of men's football - a case study in Denmark

    DEFF Research Database (Denmark)

    Pfister, Gertrud Ursula; Lenneis, Verena; Mintert, Svenja-Maria

    2013-01-01

    Football is an invention by men for men, and today, the majority of players and fans are men. There is an abundance of literature on football and fandom; however, gender is mostly not an issue in these publications. Research about female football supporters and fans is very limited. This is also...... to a ‘man’s world’ and what are their roles in this ‘male environment’? The statements of interviewees revealed that female fans have to cope with a measure of sexism, but that they can adopt the men’s perspectives in order to be accepted as ‘authentic fans’. Other women reacted on men’s domination...

  8. Performance Study and CFD Predictions of a Ducted Fan System

    Science.gov (United States)

    Abrego, Anita I.; Chang, I-Chung; Bulaga, Robert W.; Rutkowski, Michael (Technical Monitor)

    2002-01-01

    An experimental investigation was completed in the NASA Ames 7 by 10-Foot Wind Tunnel to study the performance characteristics of a ducted fan. The goal of this effort is to study the effect of ducted fan geometry and utilize Computational Fluid Dynamics (CFD) analysis to provide a baseline for correlation. A 38-inch diameter, 10-inch chord duct with a five-bladed fixed-pitch fan was tested. Duct performance data were obtained in hover, vertical climb, and forward flight test conditions. This paper will present a description of the test, duct performance results and correlation with CFD predictions.

  9. Introduction of a Cooling-Fan Efficiency Index

    DEFF Research Database (Denmark)

    Schiavon, S.; Melikov, Arsen Krikor

    2009-01-01

    , while cooling capacity and efficiency of energy use are unknown. To address this knowledge gap, this paper introduces the cooling-fan efficiency (CFE) index, defined as the ratio between the cooling effect (measured with a thermal manikin) generated by the device and its power consumption. The index...... cooling effect and an index for determining fan efficiency, such as the CFE index proposed in this study, need to be developed. The cooling fans generate a nonuniform velocity field around occupants, which cannot be described with a single air-velociry value. Therefore, it is not clear how to apply...

  10. Energy from forests in the countries of the Congo Basin; L'energie forestiere dans les pays du bassin du Congo

    Energy Technology Data Exchange (ETDEWEB)

    Boundzanga, G.C. [Centre National d' Inventaire et d' Amenagement des Ressources Forestieres et Fauniques du Zaire (Zaire); Loumeto, J. [Brazzaville Univ., Brazzaville (Congo, The Democratic Republic of the). Faculty of Science

    2009-07-15

    Deforestation and overexploitation of timber in the forests of the Congo Basin in Central Africa has resulted in environmental damage. This article listed the consumption of wood energy for Cameroon, the Central African Republic, Gabon, Republic of the Congo, Democratic Republic of the Congo, and Equatorial Guinea and emphasized the need to create a process to enable better management of forest resources by assigning more transparent concessions and establishing standards for the regeneration of the forest. Wood energy continues to be used in urban centres despite advances being made to promote the use of butane gas. As such, the ecological damage is visible in densely populated areas despite the fact that vast amounts of land would be well suited for tree plantations. 2 refs., 1 tab., 2 figs.

  11. [Approach to sexuality in an AIDS context in Congo].

    Science.gov (United States)

    Courtois, R; Mullet, E; Malvy, D

    2001-01-01

    The pandemic due to the human immunodeficiency virus (HIV) is extensive in Sub-Saharan Africa and especially in Congo. Congo is a small country on the Atlantic coast and characterized by plentiful equatorial forests and low population density (essentially urban). In Congo, there is a high prevalence of HIV. The social and economic consequences of AIDS add to those of a recent civil war in 1997. There were fratricidal confrontations before and after this period. These confrontations have led to a massive exodus of the inhabitants of the capital, Brazzaville, to the forests and neighbouring cities, essentially towards Pointe-Noire. Pointe-Noire, chief place of the region of Kouilou, in the South of the country, is the second city of Congo and the economic Capital. It is undoubtedly for this reason that it has been globally saved. In this context, a sanitary policy of prevention of sexual risky behavior can appear as a challenge. While it supposes a better knowledge of the sexual activity of the young people, it cannot be dissociated from the analysis of the other factors. These factors can be of socio-economic political or cultural order. Thus the influence of cultural variables in the field of sexuality is certainly preponderant in African countries, where sexuality is taboo. Sexuality is a private matter (personal intimacy and the couple), but concerns also the family (in the sense of membership in an extended domestic group or in a system of relationship) in its aspects related to procreation and to the social field (power, alliances). Such individual behaviour can be lived as a questioning of the social order. In this article, the authors question the place of sexuality in Congo, particularly based on the work of anthropologists [2, 6, 7, 9]. Research in the field of sexuality at adolescence is rather recent in France and investigations that have been done in Congo these last ten years do not exist. Meetings and exchanges in 1998 with high-school pupils and

  12. Characterization of Terrestrial Water Dynamics in the Congo Basin Using GRACE and Satellite Radar Altimetry

    Science.gov (United States)

    Lee, Lyongki; Beighley, R. Edward; Alsdorf, Douglas; Jung, Hahn Chul; Shum, C. K.; Duan, Jianbin; Guo, Junyi; Yamazaki, Dai; Andreadis, Konstantinos

    2011-01-01

    The Congo Basin is the world's third largest in size (approximately 3.7 million km^2), and second only to the Amazon River in discharge (approximately 40,200 cms annual average). However, the hydrological dynamics of seasonally flooded wetlands and floodplains remains poorly quantified. Here, we separate the Congo wetland into four 3 degree x 3 degree regions, and use remote sensing measurements (i.e., GRACE, satellite radar altimeter, GPCP, JERS-1, SRTM, and MODIS) to estimate the amounts of water filling and draining from the Congo wetland, and to determine the source of the water. We find that the amount of water annually filling and draining the Congo wetlands is 111 km^3, which is about one-third the size of the water volumes found on the mainstem Amazon floodplain. Based on amplitude comparisons among the water volume changes and timing comparisons among their fluxes, we conclude that the local upland runoff is the main source of the Congo wetland water, not the fluvial process of river-floodplain water exchange as in the Amazon. Our hydraulic analysis using altimeter measurements also supports our conclusion by demonstrating that water surface elevations in the wetlands are consistently higher than the adjacent river water levels. Our research also highlights differences in the hydrology and hydrodynamics between the Congo wetland and the mainstem Amazon floodplain.

  13. ADSORPSI CONGO RED PADA HUMIN HASIL ISOLASI DARI TANAH HUTAN DAMAR BATURRADEN PURWOKERTO

    Directory of Open Access Journals (Sweden)

    Roy Andreas

    2008-05-01

    Full Text Available Congo red is one of dyes-stuff in textile industry wastwater. If it is thrown directly without waste management process, the dyes could pollute environtment, especially soil. Humin has OH phenolic and carboxylic functional group which can interacted with congo red. The aim of this study is recognize humin characteristic from the soil of Baturraden resin forest, determine the adsorption capacity and isotherm adsorption pattern of congo red by humin from the soil of Baturraden resin forest. Humin in this study is isolated from the soil of Baturraden resin forest. soil cleared of gravel and dirt, then it extracted by using NaOH of nitrogen atmosphere and purified to applies mixture HCl:HF. Humin that is obtained is used to be interacted with dyes with various contact time, various of pH and concentration of congo red so that the adsorption capacities and isotherm adsorption pattern can be obtained. Result of the study showed that the humin has water content 34.92 %, dust content 8.64 %, total acidity 475 cmol/Kg, carboxylic rate 272.5 cmol/Kg, and OH Phenolic rate 202.5 cmol/Kg. The optimum contact time of congo red adsorption by humin is 40 minutes, with optimum pH is 7, adsorption capacities 57.14 mg/g and isotherm adsorption pattern of congo red by humin is follow the pattern of Langmuir isotherm adsorption.

  14. Soil phosphorus dynamics as affected by Congo grass and P fertilizer

    Directory of Open Access Journals (Sweden)

    Ciro Antonio Rosolem

    2014-08-01

    Full Text Available Some plant species can change soil phosphorus (P availability and this may be an important tool in managing tropical high fixing phosphorus soils. An experiment was conducted to evaluate phosphorus transformations in the soil and phosphatase activity during periods of Congo grass (Brachiaria ruziziensis, Germain et Evrard growth in two tropical soils receiving 20, 40, 80, 160 mg dm-3 of inorganic P. Plants were grown for 84 days in 8-L pots. Acid phosphatase activity, P in the microbial mass, soil organic and inorganic P and P accumulation by Congo grass were evaluated. Phosphorus fertilization increased soil P availability, Congo grass yields and P accumulation in the plant. On average, less labile P forms in the soil were not changed by Congo grass; however, the P in the soil extracted with HCl (P-Ca - non labil form decreased. This decrease may have resulted from the combination of the presence of grass and phosphatase capacity to dissolve less available P in the soil. Thus, soil exploration by Congo grass roots and the subsequent extraction of calcium phosphate may have increased the P concentration in the plant tissue. Despite the decrease in the P extracted from the soil with HCl resulting in increased labile P forms in the soil, the effect of Congo grass on the availability of P depends on the soil type.

  15. Congo grass grown in rotation with soybean affects phosphorus bound to soil carbon

    Directory of Open Access Journals (Sweden)

    Alexandre Merlin

    2014-06-01

    Full Text Available The phosphorus supply to crops in tropical soils is deficient due to its somewhat insoluble nature in soil, and addition of P fertilizers has been necessary to achieve high yields. The objective of this study was to examine the mechanisms through which a cover crop (Congo grass - Brachiaria ruziziensis in rotation with soybean can enhance soil and fertilizer P availability using long-term field trials and laboratory chemical fractionation approaches. The experimental field had been cropped to soybean in rotation with several species under no-till for six years. An application rate of no P or 240 kg ha-1 of P2O5 had been applied as triple superphosphate or as Arad rock phosphate. In April 2009, once more 0.0 or 80.0 kg ha-1 of P2O5 was applied to the same plots when Congo grass was planted. In November 2009, after Congo grass desiccation, soil samples were taken from the 0-5 and 5-10 cm depth layer and soil P was fractionated. Soil-available P increased to the depth of 10 cm through growing Congo grass when P fertilizers were applied. The C:P ratio was also increased by the cover crop. Congo grass cultivation increased P content in the soil humic fraction to the depth of 10 cm. Congo grass increases soil P availability by preventing fertilizer from being adsorbed and by increasing soil organic P.

  16. Congo Red Interactions with Curli-Producing E. coli and Native Curli Amyloid Fibers.

    Directory of Open Access Journals (Sweden)

    Courtney Reichhardt

    Full Text Available Microorganisms produce functional amyloids that can be examined and manipulated in vivo and in vitro. Escherichia coli assemble extracellular adhesive amyloid fibers termed curli that mediate adhesion and promote biofilm formation. We have characterized the dye binding properties of the hallmark amyloid dye, Congo red, with curliated E. coli and with isolated curli fibers. Congo red binds to curliated whole cells, does not inhibit growth, and can be used to comparatively quantify whole-cell curliation. Using Surface Plasmon Resonance, we measured the binding and dissociation kinetics of Congo red to curli. Furthermore, we determined that the binding of Congo red to curli is pH-dependent and that histidine residues in the CsgA protein do not influence Congo red binding. Our results on E. coli strain MC4100, the most commonly employed strain for studies of E. coli amyloid biogenesis, provide a starting point from which to compare the influence of Congo red binding in other E. coli strains and amyloid-producing organisms.

  17. COOLING FAN AND SYSTEM PERFORMANCE AND EFFICIENCY IMPROVEMENTS

    Energy Technology Data Exchange (ETDEWEB)

    Ronald Dupree

    2005-07-31

    Upcoming emissions regulations (Tiers 3, 4a and 4b) are imposing significantly higher heat loads on the cooling system than lesser regulated machines. This work was a suite of tasks aimed at reducing the parasitic losses of the cooling system, or improving the design process through six distinct tasks: 1. Develop an axial fan that will provide more airflow, with less input power and less noise. The initial plan was to use Genetic Algorithms to do an automated fan design, incorporating forward sweep for low noise. First and second generation concepts could not meet either performance or sound goals. An experienced turbomachinery designer, using a specialized CFD analysis program has taken over the design and has been able to demonstrate a 5% flow improvement (vs 10% goal) and 10% efficiency improvement (vs 10% goal) using blade twist only. 2. Fan shroud developments, using an 'aeroshroud' concept developed at Michigan State University. Performance testing at Michigan State University showed the design is capable of meeting the goal of a 10% increase in flow, but over a very narrow operating range of fan performance. The goal of 10% increase in fan efficiency was not met. Fan noise was reduced from 0 to 2dB, vs. a goal of 5dB at constant airflow. The narrow range of fan operating conditions affected by the aeroshroud makes this concept unattractive for further development at this time 3. Improved axial fan system modeling is needed to accommodate the numbers of cooling systems to be redesigned to meet lower emissions requirements. A CFD fan system modeling guide has been completed and transferred to design engineers. Current, uncontrolled modeling practices produce flow estimates in some cases within 5% of measured values, and in some cases within 25% of measured values. The techniques in the modeling guide reduced variability to the goal of + 5% for the case under study. 4. Demonstrate the performance and design versatility of a high performance fan. A

  18. Life, death and revival of debris-flow fans on Earth and Mars : fan dynamics and climatic inferences

    OpenAIRE

    Haas, T.

    2016-01-01

    Alluvial fans are ubiquitous landforms in high-relief regions on Earth and Mars. They have a semi-conical shape and are located at the transition between highlands and adjacent basins. Alluvial fans can form by a range of processes including debris flows, which are water-laden masses of soil and rock with volumetric sediment concentrations exceeding 40%. In this thesis, I aim to (1) unravel the formative dynamics of debris-flow fans and, building on these insights, to (2) reconstruct hydrolog...

  19. Is the turbidite facies association scheme valid for interpreting ancient submarine fan environments?

    Science.gov (United States)

    Shanmugam, G.; Damuth, J. E.; Moiola, R. J.

    1985-04-01

    Although turbidite facies reflect only processes of deposition, turbidite facies associations are routinely used to identify ancient submarine-fan subenvironments (e.g., upper fan, channel, lobe, etc.). The assumption that process of deposition also reflects environment of deposition may not be valid for the following reasons: (1) Mutti and Ricci Lucchi's facies association scheme for submarine fans has been developed exclusively from ancient turbidite sequences; however, the true relationship between such turbidite facies associations and related fan subenvironments has not been confirmed from modern fans; (2) individual channel-levee systems of many modern submarine fans are in many cases large enough to contain the entire ancient fan systems on which these facies associations are based; (3) large channel-levee systems comparable to those of modern fans have not been recognized in outcrops. Consequently, the validity of turbidite facies associations for interpreting ancient submarine-fan subenvironments must be considered tenuous until confirmed in modern fans.

  20. PLSS 2.5 Fan Design and Development

    Science.gov (United States)

    Quinn, Gregory; Carra, Michael; Converse, David; Chullen, Cinda

    2015-01-01

    NASA is building a high fidelity prototype of an advanced portable life support system (PLSS) as part of the Advanced Exploration Systems Program. This new PLSS, designated as PLSS 2.5, will advance component technologies and systems knowledge in order to inform a future flight program. The oxygen ventilation loop of its predecessor, PLSS 2.0, is driven by a centrifugal fan developed using specifications from the Constellation Program. PLSS technology and system parameters have matured to the point where the existing fan will not perform adequately for the new prototype. In addition, areas of potential improvement have been identified with the existing fan that could be addressed in a new design. As a result, a new fan was designed and tested for the PLSS 2.5.

  1. Autonomous Composite Fan Containment Integrity Monitoring (AUTOCONFIRM) System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — New engine fan blade containment structures are being manufactured with advanced composite structures such that they can withstand blade-out events. The use of...

  2. Redefining genderswap fan fiction: A Sherlock case study

    Directory of Open Access Journals (Sweden)

    Ann McClellan

    2014-09-01

    Full Text Available Using BBC Sherlock (2010– fan fiction as case study, this article looks at how fans use and understand such concepts as biological sex and gender in genderswap fan fiction, arguing that the label often minimizes the importance of the physical body in determining gender identity. The label genderswap, most often used to describe stories where characters have become differently sexed, reflects and reinforces common cultural misunderstandings about differences between sex and gender. By teasing out definitions of genderswap, sex, gender, cisgender, and transgender, the article analyzes what genderswap includes and excludes from discussions of gender and identity within contemporary fan fiction, ultimately arguing for a broader conceptual understanding that grounds the genre within contemporary transgender theory.

  3. Field testing the prototype BNL fan-atomized oil burner

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, R.; Celebi, Y. [Brookhaven National Lab., Upton, NY (United States)

    1995-04-01

    BNL has developed a new oil burner design referred to as the Fan Atomized burner System. The primary objective of the field study was to evaluate and demonstrate the reliable operation of the Fan Atomized Burner. The secondary objective was to establish and validate the ability of a low firing rate burner (0.3-0.4 gph) to fully satisfy the heating and domestic hot water load demands of an average household in a climate zone with over 5,000 heating-degree-days. The field activity was also used to evaluate the practicality of side-wall venting with the Fan Atomized Burner with a low stack temperature (300F) and illustrate the potential for very high efficiency with an integrated heating system approach based on the Fan Atomized Burner.

  4. Low Cost/Low Noise Variable Pitch Ducted Fan Project

    Data.gov (United States)

    National Aeronautics and Space Administration — ACI proposes a design for a Propulsor (Low Cost/Low Noise Variable Pitch Ducted Fan) that has wide application in all sectors of Aviation. Propulsor hardware of this...

  5. Why do fans attend world Wrestling Entertainment? | Kruger | South ...

    African Journals Online (AJOL)

    South African Journal for Research in Sport, Physical Education and Recreation ... at a live Smackdown event in July 2011, which was part of the WWE's world tour. ... Therefore, marketing campaigns directed at these fans should be designed ...

  6. Gender constructions and negotiations of female football fans

    DEFF Research Database (Denmark)

    Lenneis, Verena; Pfister, Gertrud Ursula

    2015-01-01

    While both the media and the academic literature focus primarily on male fans, in particular on violence and the prevention of hooliganism, little is known about female football supporters. This is also true of Denmark, a country that is known for its high degree of gender equality. This article...... "hypermasculinity" nor "emphasised femininity" in their gender performances. Female fans do not only comply with and reproduce the rules of conduct in the stadium but also apply different forms of resistance against sexism and the domination of men in the stadium – both on the field and in the stands. The founding...... aims to give insight into gender constructions and negotiations of female football fans in the stands. Drawing on a social constructivist perspective to gender and Bourdieu's (1984) approaches to field, capital and habitus, we explored the experiences and opinions of female fans. The methods employed...

  7. Modeling and ecodesigning crossflow ventilation fans with Mathematica

    CERN Document Server

    Argentini, Gianluca

    2010-01-01

    The efficiency of a simple model of crossflow fan is maximized when the geometry depends on a design parameter. The flow field is numerically computed using a Galerkin method for solving a Poisson partial differential equation.

  8. Pathological effects of cyanobacteria on sea fans in southeast Florida.

    Science.gov (United States)

    Kiryu, Y; Landsberg, J H; Peters, E C; Tichenor, E; Burleson, C; Perry, N

    2015-07-01

    In early August 2008, observations by divers indicated that sea fans, particularly Gorgonia ventalina, Gorgonia flabellum, and Iciligorgia schrammi, were being covered by benthic filamentous cyanobacteria. From August 2008 through January 2009 and again in April 2009, tissue samples from a targeted G. ventalina colony affected by cyanobacteria and from a nearby, apparently healthy (without cyanobacteria) control colony, were collected monthly for histopathological examination. The primary cellular response of the sea fan to overgrowth by cyanobacteria was an increase in the number of acidophilic amoebocytes (with their granular contents dispersed) that were scattered throughout the coenenchyme tissue. Necrosis of scleroblasts and zooxanthellae and infiltration of degranulated amoebocytes were observed in the sea fan surface tissues at sites overgrown with cyanobacteria. Fungal hyphae in the axial skeleton were qualitatively more prominent in cyanobacteria-affected sea fans than in controls.

  9. Sediments and processes on a small stream-flow dominated, devonian alluvial fan, Shetland Islands

    Science.gov (United States)

    Allen, Philip A.

    1981-05-01

    The main conglomerate type of a small Devonian alluvial fan in Shetland, northern Britain, is an inverse to normally graded framework-supported gravel. The sedimentological details of these beds and fundamental considerations of the mechanics of movement of highly concentrated flows suggests that neither debris-flow nor grain-flow were responsible for the deposition of these conglomerates. On the contrary, these inverse to normally graded conglomerates were deposited by water as thick gravel sheets with little topographic relief, but broadly analogous to longitudinal bars. They were deposited under high aggradation conditions first on the rising and then on the falling flood. The high concentration of material in transport on the rising and peak flood was responsible for the polymodal and unstratified nature of the conglomerates. As the flood waned, normal grading was developed and a preferred horizontal fabric was produced under low concentrations of sediment. Other conglomerate types, comparatively of lesser importance, were deposited from highly concentrated clast dispersions and are notably richer in matrix and locally possess inverse grading. The hydrological environment was one of flashy discharges of short duration but of high velocity. Flow was dissipated rapidly, perhaps due to extreme water loss. This example from the Devonian of Shetland provides an interesting alternative to the mass-transport dominated fan models currently in vogue.

  10. Noise Generation by Fans with Supersonic Tip Speeds

    Science.gov (United States)

    Glegg, Stewart; Envia, Edmane (Technical Monitor)

    2003-01-01

    Fan noise continues to be a significant issue for commercial aircraft engines and there still exists a requirement for improved understanding of the fundamental issues associated with fan noise source mechanisms. At the present time, most of the prediction methods identify the dominant acoustic sources to be associated with the stator vanes or blade trailing edges which are downstream of the fan face. However recent studies have shown that acoustic waves are significantly attenuated as they propagate upstream through a rotor, and if the appropriate corrections are applied, sound radiation from the engine inlet is significantly underpredicted. The prediction models can only be applied to fans with subsonic tip speeds. In contrast, most aircraft engines have fan tip speeds which are transonic and this implies an even higher attenuation for upstream propagating acoustic waves. Consequently understanding how sound propagates upstream through the fan is an important, and not well understood phenomena. The objective of this study is to provide improved insight into the upstream propagation effects through a rotor which are relevant to full scale engines. The focus of this study is on broadband fan noise generated by boundary layer turbulence interacting with the trailing edges of the fan blades. If this source mechanism is important upstream of the fan, the sound must propagate upstream through a transonic non uniform flow which includes large gradients and non linearities. Developing acoustic propagation models in this type of flow is challenging and currently limited to low frequency applications, where the frequency is of the same order as the blade passing frequency of the fan. For trailing edge noise, much higher frequencies are relevant and so a suitable approach needs to be developed, which is not limited by an unacceptably large computational effort. In this study we are in the process of developing a computational method which applies for the high frequencies of

  11. Should electric fans be used during a heat wave?

    Science.gov (United States)

    Jay, Ollie; Cramer, Matthew N; Ravanelli, Nicholas M; Hodder, Simon G

    2015-01-01

    Heat waves continue to claim lives, with the elderly and poor at greatest risk. A simple and cost-effective intervention is an electric fan, but public health agencies warn against their use despite no evidence refuting their efficacy in heat waves. A conceptual human heat balance model can be used to estimate the evaporative requirement for heat balance, the potential for evaporative heat loss from the skin, and the predicted sweat rate, with and without an electrical fan during heat wave conditions. Using criteria defined by the literature, it is clear that fans increase the predicted critical environmental limits for both the physiological compensation of endogenous/exogenous heat, and the onset of cardiovascular strain by an air temperature of ∼3-4 °C, irrespective of relative humidity (RH) for the young and elderly. Even above these critical limits, fans would apparently still provide marginal benefits at air temperatures as high as 51.1 °C at 10%RH for young adults and 48.1 °C at 10%RH for the elderly. Previous concerns that dehydration would be exacerbated with fan use do not seem likely, except under very hot (>40 °C) and dry (conditions, when predicted sweat losses are only greater with fans by a minor amount (∼20-30 mL/h). Relative to the peak outdoor environmental conditions reported during ten of the most severe heat waves in recent history, fan use would be advisable in all of these situations, even when reducing the predicted maximum sweat output for the elderly. The protective benefit of fans appears to be underestimated by current guidelines. Copyright © 2014 Elsevier Ltd and The Ergonomics Society. All rights reserved.

  12. On the Optimal Selection of Electrical Machines Fans

    Directory of Open Access Journals (Sweden)

    Mădălin Costin

    2014-09-01

    Full Text Available In this paper an analytic relationship for electrical machine fan design has been developed. In the particularly case of salient poles synchronous machine (with salient poles – for electromagnetic field excitation or surface mounded permanent magnet, this approach allowed to express the fan power as a function of machine middle axe air gap. This analytic foundation developed may leads to different optimization criteria as specific active materials or costs. Numerical simulations confirm our approach.

  13. Sport Fan Motivation: Are You Going To The Game?

    OpenAIRE

    Johannes A. Wiid; Cant, Michael C.

    2015-01-01

    Every individual or group consume sporting events for different reasons and are therefore motivated in different ways. People consuming sport events can be referred to as sport fans, someone who is enthusiastic about a particular sport, an athlete or someone who is motivated to make the effort to attend a live sporting event. Research on sport consumption motivation had led to the development of the Sport Fan Motivation Scale (SFMS), which consists of eight motives namely, eustress, self-este...

  14. Simulation of fan topography and soil profile using a coupled soilscape-landscape evolution model

    Science.gov (United States)

    Welivitiya, Dimuth; Willgoose, Garry; Hancock, Greg

    2017-04-01

    In this study the evolution of a fluvial fan, its topography and soil profile grading under erosion and deposition and soil profile weathering was simulated using SSPAM coupled soil-landscape evolution model. A constant rainfall was simulated on a synthetic landform and a fluvial fan depositional structure was allowed to form at the latter part of the landform. At each time step the geomorphological and particle size distribution information of the fan was recorded. Using this recorded information, the evolutionary characteristics of the fan as well as the surface and subsurface sediment characteristics was examined and compared with experimental and field observation data. Different fan profile sections were also derived from the recorded data and analysed. The simulation produced a fluvial fan semicircular in shape, with concave up long profiles and convex up cross profiles. The surface sediment sizes of the simulated fan were coarsest near the fan apex and fines toward the fan toe with coarse grained sediment filaments extending radially from the fan apex. These geomorphological features and surface sediment distribution agrees well with field observations of natural fans. The results of the simulation also show that the fan develops as a result of the channel bringing sediments in to the fan and periodically changing its path due to steepening of channel gradient by sediment deposition. The position of the channel is fixed at the fan apex and the channel path constantly changes along any radial direction form the fan apex. This process is remarkably similar to the process of "Fan head trenching" described in literature which is the dominant process in fluvial fan development in the field. Finally, the analysis of fan cross-sections revealed complex sediment layering patterns in the fan profile. The simulation results of the SSSPAM coupled soilscape-landscape evolution model provide qualitatively correct geomorphological and sedimentary characterization of the

  15. Experimental and Numerical Investigation of a 60cm Diameter Bladeless Fan

    OpenAIRE

    mohammad jafari; Hossein Afshin; Bijan Farhanieh; Hamidreza bozorgasareh

    2016-01-01

    Bladeless fan is a novel type of fan with an unusual geometry and unique characteristics. This type of fan has been recently developed for domestic applications in sizes typically up to 30cm diameter. In the present study, a Bladeless fan with a diameter of 60cm was designed and constructed, in order to investigate feasibility of its usage in various industries with large dimensions. Firstly, flow field passed through this fan was studied by 3D modeling. Aerodynamic and aeroacoust...

  16. Damage-Tolerant Fan Casings for Jet Engines

    Science.gov (United States)

    2006-01-01

    All turbofan engines work on the same principle. A large fan at the front of the engine draws air in. A portion of the air enters the compressor, but a greater portion passes on the outside of the engine this is called bypass air. The air that enters the compressor then passes through several stages of rotating fan blades that compress the air more, and then it passes into the combustor. In the combustor, fuel is injected into the airstream, and the fuel-air mixture is ignited. The hot gasses produced expand rapidly to the rear, and the engine reacts by moving forward. If there is a flaw in the system, such as an unexpected obstruction, the fan blade can break, spin off, and harm other engine components. Fan casings, therefore, need to be strong enough to contain errant blades and damage-tolerant to withstand the punishment of a loose blade-turned-projectile. NASA has spearheaded research into improving jet engine fan casings, ultimately discovering a cost-effective approach to manufacturing damage-tolerant fan cases that also boast significant weight reduction. In an aircraft, weight reduction translates directly into fuel burn savings, increased payload, and greater aircraft range. This technology increases safety and structural integrity; is an attractive, viable option for engine manufacturers, because of the low-cost manufacturing; and it is a practical alternative for customers, as it has the added cost saving benefits of the weight reduction.

  17. Potential Global Benefits of Improved Ceiling Fan Energy Efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Sathaye, Nakul [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Phadke, Amol [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Shah, Nihar [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Letschert, Virginie [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2012-10-31

    Ceiling fans contribute significantly to residential electricity consumption, both in an absolute sense and as a proportion of household consumption in many locations, especially in developing countries in warm climates. However, there has been little detailed assessment of the costs and benefits of efficiency improvement options for ceiling fans and the potential resulting electricity consumption and greenhouse gas (GHG) emissions reductions. We analyze the costs and benefits of several options to improve the efficiency of ceiling fans and assess the global potential for electricity savings and GHG emission reductions with more detailed assessments for India, China, and the U.S. We find that ceiling fan efficiency can be cost-effectively improved by at least 50% using commercially available technology. If these efficiency improvements are implemented in all ceiling fans sold by 2020, 70 terrawatt hours per year (TWh/year) could be saved and 25 million metric tons of carbon dioxide (CO2) emissions per year could be avoided, globally. We assess how policies and programs such as standards, labels, and financial incentives can be used to accelerate the adoption of efficient ceiling fans in order to realize this savings potential.

  18. COOLING FAN AND SYSTEM PERFORMANCE AND EFFICIENCY IMPROVEMENTS

    Energy Technology Data Exchange (ETDEWEB)

    Ronald Dupree

    2005-07-31

    Upcoming emissions regulations (Tiers 3, 4a and 4b) are imposing significantly higher heat loads on the cooling system than lesser regulated machines. This work was a suite of tasks aimed at reducing the parasitic losses of the cooling system, or improving the design process through six distinct tasks: 1. Develop an axial fan that will provide more airflow, with less input power and less noise. The initial plan was to use Genetic Algorithms to do an automated fan design, incorporating forward sweep for low noise. First and second generation concepts could not meet either performance or sound goals. An experienced turbomachinery designer, using a specialized CFD analysis program has taken over the design and has been able to demonstrate a 5% flow improvement (vs 10% goal) and 10% efficiency improvement (vs 10% goal) using blade twist only. 2. Fan shroud developments, using an 'aeroshroud' concept developed at Michigan State University. Performance testing at Michigan State University showed the design is capable of meeting the goal of a 10% increase in flow, but over a very narrow operating range of fan performance. The goal of 10% increase in fan efficiency was not met. Fan noise was reduced from 0 to 2dB, vs. a goal of 5dB at constant airflow. The narrow range of fan operating conditions affected by the aeroshroud makes this concept unattractive for further development at this time 3. Improved axial fan system modeling is needed to accommodate the numbers of cooling systems to be redesigned to meet lower emissions requirements. A CFD fan system modeling guide has been completed and transferred to design engineers. Current, uncontrolled modeling practices produce flow estimates in some cases within 5% of measured values, and in some cases within 25% of measured values. The techniques in the modeling guide reduced variability to the goal of + 5% for the case under study. 4. Demonstrate the performance and design versatility of a high performance fan. A

  19. Broadband Liner Optimization for the Source Diagnostic Test Fan

    Science.gov (United States)

    Nark, Douglas M.; Jones, Michael G.

    2012-01-01

    The broadband component of fan noise has grown in relevance with the utilization of increased bypass ratio and advanced fan designs. Thus, while the attenuation of fan tones remains paramount, the ability to simultaneously reduce broadband fan noise levels has become more appealing. This paper describes a broadband acoustic liner optimization study for the scale model Source Diagnostic Test fan. Specifically, in-duct attenuation predictions with a statistical fan source model are used to obtain optimum impedance spectra over a number of flow conditions for three liner locations in the bypass duct. The predicted optimum impedance information is then used with acoustic liner modeling tools to design liners aimed at producing impedance spectra that most closely match the predicted optimum values. Design selection is based on an acceptance criterion that provides the ability to apply increased weighting to specific frequencies and/or operating conditions. Typical tonal liner designs targeting single frequencies at one operating condition are first produced to provide baseline performance information. These are followed by multiple broadband design approaches culminating in a broadband liner targeting the full range of frequencies and operating conditions. The broadband liner is found to satisfy the optimum impedance objectives much better than the tonal liner designs. In addition, the broadband liner is found to provide better attenuation than the tonal designs over the full range of frequencies and operating conditions considered. Thus, the current study successfully establishes a process for the initial design and evaluation of novel broadband liner concepts for complex engine configurations.

  20. THz Beam Shaper Realizing Fan-Out Patterns

    Science.gov (United States)

    Liebert, K.; Rachon, M.; Siemion, A.; Suszek, J.; But, D.; Knap, W.; Sypek, M.

    2017-08-01

    Fan-out elements create an array of beams radiating at particular angles along the propagation axis. Therefore, they are able to form a matrix of equidistant spots in the far-field diffraction region. In this work, we report on the first fan-out structures designed for the THz range of radiation. Two types of light-dividing fan-out structures are demonstrated: (i) the 3×1 matrix fan-out structure based on the optimized binary phase grating and (ii) the 3×3 fan-out structure designed on the basis of the well-known Dammann grating. The structures were generated numerically and manufactured using the 3D printing technique with polyamide PA12. To obtain equal powers and symmetry of diffracted beams, the computer-aided optimization algorithm was used. Diffractive optical elements designed for 140 and 282 GHz were evaluated experimentally at both these frequencies using illumination with the wavefront coming from the point-like source. Described fan-out elements formed uniform intensity and equidistant energy distribution in agreement with the numerical simulations.

  1. "The florals": Female fans over 50 in the Sherlock fandom

    Directory of Open Access Journals (Sweden)

    Line Nybro Petersen

    2017-03-01

    Full Text Available This article uses e-mail interviews with nine female fans to explore what it means to be a fan over the age of 50 of the popular BBC drama Sherlock (2010–. The research aims to better understand the role of fandom in later life, in particular how the participants in this study negotiate their perceptions of their subjective age in relation to being a fan in this part of their life course. This study combines theory on cultural gerontology with fan studies and mediatization theory in order to understand the dynamics and processes that guide fans' negotiations of subjective age as well as the role of fan practices and the affordances of social media in these processes. I argue that fandom, as a manifestation of a mediatized culture, augments the relevance of subjective age and informs the way in which participants in middle and later life perceive and negotiate their own subjective age specifically in relation to fandom as youth culture, women's passion, and creativity.

  2. Fan Ky不等式的一个改进%A Refinement of Fan Ky's Inequality

    Institute of Scientific and Technical Information of China (English)

    周昱; 高明哲

    2007-01-01

    利用改进的H(o)lder不等式并借助于正交矩阵的行列式的积分表示法建立了Fan Ky不等式的一个有意义的改进.当A,B为n阶非奇异矩阵时,给出了新创建不等式的一个推广.特别当n=1时,得到了Young不等式的一个很强的结果.

  3. Dynamic Bowtie for Fan-beam CT

    CERN Document Server

    Liu, Fenglin; Cong, Wenxiang; Hsieh, Scott; Pelc, Norbert

    2013-01-01

    A bowtie is a filter used to shape an x-ray beam and equalize its flux reaching different detector channels. For development of spectral CT with energy-discriminative photon-counting (EDPC) detectors, here we propose and evaluate a dynamic bowtie for performance optimization based on a patient model or a scout scan. Our dynamic bowtie modifies an x-ray beam intensity profile by mechanical rotation and adaptive adjustment of the x-ray source flux. First, a mathematical model for dynamic bowtie filtering is established for an elliptical section in fan-beam geometry, and the contour of the optimal bowtie is derived. Then, numerical simulation is performed to compare the performance of the dynamic bowtie in the cases of an ideal phantom and a realistic cross-section relative to the counterparts without any bowtie and with a fixed bowtie respectively. Our dynamic bowtie can equalize the expected numbers of photons in the case of an ideal phantom. In practical cases, our dynamic bowtie can effectively reduce the dy...

  4. Characterisation of fan-beam collimators.

    Science.gov (United States)

    Pareto, D; Pavía, J; Falcón, C; Juvells, I; Cot, A; Ros, D

    2001-02-01

    Fan-beam collimators offer a good balance between resolution and noise. The collimator response may be included in iterative reconstruction algorithms in order to improve single-photon emission tomography (SPET) resolution. To this end, accurate determination of the focal region and characterisation of the collimator response as a function of the source co-ordinates must be performed. In this paper, a method to characterise fanbeam collimators is evaluated. First, we calculated the real focal region and the accuracy of the collimator convergence. Then, we confirmed the hypothesis that Gaussian distributions adequately fit the collimator responses, although no individualised treatment was performed for the tails of detector response which are associated with scattering and septal penetration. Finally, analytical functions were used to model the resolution and sensitivity. The parameter values in these functions were obtained from experimental measures by non-linear regression fitting. Our findings show differences of 1.43% between nominal and real focal length and standard deviations of 2.5 mm in the x-direction and 7.1 mm in the y-direction for the focal convergence. The correlation coefficients between experimental and predicted values were 0.994 for resolution and 0.991 for sensitivity. As a consequence, the proposed method can be used to characterise the collimator response.

  5. Review: Bettina Fritzsche (2003. Pop-Fans. Studie einer Mädchenkultur [Pop-Fans: Study of a Girl Culture

    Directory of Open Access Journals (Sweden)

    Lothar Mikos

    2006-05-01

    Full Text Available This study focuses on the "girl culture" created by fans of boy groups and girl groups. The central case study is used to examine fan practices as cultural practices using reconstructive and documentary methodologies, and to assess the normative demands placed on young people. The study centers on the question of gender socialization by mediated symbolic resources, and shows that fan culture is a self-determined space in which girls can negotiate normative demands and engage with questions of gender, sexuality and the body, testing conformity and obstinacy. Fan activities are presented as part of the self-empowerment of girls. The study makes an important contribution to the research of a specific girl culture. It shows in a brilliant way how media representations are used as symbolic material in everyday cultural practices. URN: urn:nbn:de:0114-fqs0603187

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

    Science.gov (United States)

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

    2016-01-01

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

  7. Sedimentology and hydrocarbon habitat of the submarine-fan deposits of the Central Carpathian Paleogene Basin (NE Slovakia)

    Energy Technology Data Exchange (ETDEWEB)

    Sotak, J. [Slovak Academy of Sciences, Banska Bystrica (Slovakia). Geological Institute; Pereszlenyi, M. [VVNP Research Oil Company for Exploration and Production, Bratislava (Slovakia); Marschalko, R.; Starek, D. [Slovak Academy of Sciences, Bratislava (Slovakia). Geological Institute; Milicka, J. [Comenius University, Bratislava (Slovakia). Dept. of Geochemistry

    2001-01-01

    The Central Carpathian Paleogene Basin accommodates a subsiding area of the destructive plate-margin. The basin history comprises marginal faulting and alluvial fan accumulation (E{sub 2}); transgressive onlap by shoreface sediments and carbonate platform deposits (E{sub 2}); glacio-eustatic regression induced by cooling (Terminal Eocene Event); forced regression, tectonic subsidence and growth-fault accumulation of basin-floor and slope fans (E{sub 3}); decelerating subsidence, aggradation and sea-level rising during the mud-rich deposition (O{sub 1}); high-magnitude drop in sea-level (Mid-Oligocene Event), retroarc backstep of depocenters and lowstand accumulation of sand-rich fans and suprafans (O{sub 2}-M{sub 1}); subduction-related shortening and basin inversion along the northern margins affected by backthrusting and transpressional deformation (O{sub 2}-M{sub 1}). The basin-fill sequence has poor (TOC {<=} 0.5%) to fair (TOC < 1.0%) quality of source rocks. Maturity of OM ranges from initial to relic stage of HC generation. Paleogene rock-extracts display a good correlation with scarce trapped oils. 'The presence of solid bitumens and HC-rich fluid inclusions indicates overpressure conditions during HC generation and migration. Potential HC reservoirs can be expected in porous lithologies (scarp breccias), in basement highs and traps related to backthrusting, fault-propagation folding and strike-slip tectonics. (author)

  8. Lesula: a new species of Cercopithecus monkey endemic to the Democratic Republic of Congo and implications for conservation of Congo's central basin.

    Directory of Open Access Journals (Sweden)

    John A Hart

    Full Text Available In June 2007, a previously undescribed monkey known locally as "lesula" was found in the forests of the middle Lomami Basin in central Democratic Republic of Congo (DRC. We describe this new species as Cercopithecus lomamiensis sp. nov., and provide data on its distribution, morphology, genetics, ecology and behavior. C. lomamiensis is restricted to the lowland rain forests of central DRC between the middle Lomami and the upper Tshuapa Rivers. Morphological and molecular data confirm that C. lomamiensis is distinct from its nearest congener, C. hamlyni, from which it is separated geographically by both the Congo (Lualaba and the Lomami Rivers. C. lomamiensis, like C. hamlyni, is semi-terrestrial with a diet containing terrestrial herbaceous vegetation. The discovery of C. lomamiensis highlights the biogeographic significance and importance for conservation of central Congo's interfluvial TL2 region, defined from the upper Tshuapa River through the Lomami Basin to the Congo (Lualaba River. The TL2 region has been found to contain a high diversity of anthropoid primates including three forms, in addition to C. lomamiensis, that are endemic to the area. We recommend the common name, lesula, for this new species, as it is the vernacular name used over most of its known range.

  9. Genes2FANs: connecting genes through functional association networks

    Directory of Open Access Journals (Sweden)

    Dannenfelser Ruth

    2012-07-01

    Full Text Available Abstract Background Protein-protein, cell signaling, metabolic, and transcriptional interaction networks are useful for identifying connections between lists of experimentally identified genes/proteins. However, besides physical or co-expression interactions there are many ways in which pairs of genes, or their protein products, can be associated. By systematically incorporating knowledge on shared properties of genes from diverse sources to build functional association networks (FANs, researchers may be able to identify additional functional interactions between groups of genes that are not readily apparent. Results Genes2FANs is a web based tool and a database that utilizes 14 carefully constructed FANs and a large-scale protein-protein interaction (PPI network to build subnetworks that connect lists of human and mouse genes. The FANs are created from mammalian gene set libraries where mouse genes are converted to their human orthologs. The tool takes as input a list of human or mouse Entrez gene symbols to produce a subnetwork and a ranked list of intermediate genes that are used to connect the query input list. In addition, users can enter any PubMed search term and then the system automatically converts the returned results to gene lists using GeneRIF. This gene list is then used as input to generate a subnetwork from the user’s PubMed query. As a case study, we applied Genes2FANs to connect disease genes from 90 well-studied disorders. We find an inverse correlation between the counts of links connecting disease genes through PPI and links connecting diseases genes through FANs, separating diseases into two categories. Conclusions Genes2FANs is a useful tool for interpreting the relationships between gene/protein lists in the context of their various functions and networks. Combining functional association interactions with physical PPIs can be useful for revealing new biology and help form hypotheses for further experimentation. Our

  10. Structure and climate controls on the evolution of a Mid-Late Jurassic alluvial fan-delta system in the western part of Yanshan fold-and-thrust belt

    Science.gov (United States)

    Lin, Chengfa; Liu, Shaofeng; Yao, Xiang; Ma, Pengfei

    2016-04-01

    The Yanshan fold-thrust belt experienced several significant tectonic events during Mesozoic time and developed thrust fault-bounded intramontane sedimentary basins. However, elaborate works of sedimentology is inadequate in the Yanshan belt, particularly in its western segment, leading to a failure in comprehensively understanding how bounding-faults and climate change influence the basin filling processes. Our detailed sedimentological study of the Middle Jurassic Xiahuayuan Formation and Upper Jurassic-Lower Cretaceous Jiulongshan Formation in the Xiahuayuan basin of northern Hebei province, indicates a genetic relationship between the evolution of an alluvial fan-delta system and the tectonic and climate setting. The Xiahuayuan Formation was assigned to a debris flow-dominated Gilbert-type fan-delta composed of topset conglomerates, foreset massive siltstone-fine grained sandstone interbedded with lenticular conglomerate units and bottomset/lake bottom fine-grained deposits, spatially restricted to the northern part of the basin. While the lower Jiulongshan Formation was considered as a relatively small debris flow- and turbidity currents-dominated fan-delta with a single-ramp portrait, prograding into the middle part of the basin. And the upper part of Jiulongshan Formation contributed to the lake bottom component of the delta system during the forming of the Jiulongshan Formation. Our results reveal a transformation of a fan-delta from Gilbert-type to single-ramp type and the basinward migration of this fan-delta during Mid-Late Jurassic in the Xiahuayuan basin. And it is assumed that the activity of a thrust fault along the northern basin margin and the rapid switch of climate conditions from warm and humid to hot and dry triggered the transformation and migration of this fan-delta system.

  11. Depositional evolution of the Melville Bay trough-mouth fan, NW Greenland

    Science.gov (United States)

    Knutz, Paul; Gregersen, Ulrik

    2015-04-01

    The continental margin of NW Greenland bordering northern Baffin Bay is characterized by major sediment accumulations, known as Trough-Mouth Fans (TMF). The fan depocentres represent intense sediment dispersal at the terminus of ice streams that during cold climate periods provided major drainage routes of the northern Greenland Ice Sheet into Baffin Bay. The imprint of paleo-icestreams is seen by erosional troughs crossing a >250 km broad shelf region, which caps a series of sedimentary basins containing thick Mesozoic-Tertiary strata packages. This presentation provides an overview of the seismic stratigraphic division, depositional architecture and examples of seismic facies of the Melville Bay TMF using a 5-10 km grid of industry-quality 2D seismic data (TGS). The focus will primarily be on the inception and early stage of glacial fan development. Comparing the present-day topography with the regional geology shows that the paleo-icestreams exploited the Cenozoic infill of former rift basins that are more conducive to erosion than the adjoining ridges and structural highs. The TMF sequence is constructed by a series of progradational seismic units that represent successive steps in location of ice stream terminus and associated depocenters. The slope fronts of the prograding units show abundant signatures of sediment instability and mass-wasting but evidence of along-slope current-driven processes is also recognized presumably linked to interglacial sea level high-stands. The topset of each unit is characterized by planar erosion that merges landward into hummocky positive geometries with low internal reflectivity. These features are generally interpreted as subglacial landforms, e.g. terminal moraines and ice-contact deposits, associated with grounding zone wedges. Unlike the most recent TMF units deposited in front of the present trough, the oldest glacigenic units have built out from a Neogene sediment prism that forms the core of modern shallow-water banks

  12. The riverine source of CH4 and N2O from the Republic of Congo, western Congo Basin

    Science.gov (United States)

    Upstill-Goddard, Robert C.; Salter, Matthew E.; Mann, Paul J.; Barnes, Jonathan; Poulsen, John; Dinga, Bienvenu; Fiske, Gregory J.; Holmes, Robert M.

    2017-05-01

    We discuss concentrations of dissolved CH4, N2O, O2, NO3- and NH4+, and emission fluxes of CH4 and N2O for river sites in the western Congo Basin, Republic of Congo (ROC). Savannah, swamp forest and tropical forest samples were collected from the Congo main stem and seven of its tributaries during November 2010 (41 samples; wet season) and August 2011 (25 samples; dry season; CH4 and N2O only). Dissolved inorganic nitrogen (DIN: NH4++ NO3-; wet season) was dominated by NO3- (63 ± 19 % of DIN). Total DIN concentrations (1.5-45.3 µmol L-1) were consistent with the near absence of agricultural, domestic and industrial sources for all three land types. Dissolved O2 (wet season) was mostly undersaturated in swamp forest (36 ± 29 %) and tropical forest (77 ± 36 %) rivers but predominantly supersaturated in savannah rivers (100 ± 17 %). The dissolved concentrations of CH4 and N2O were within the range of values reported earlier for sub-Saharan African rivers. Dissolved CH4 was found to be supersaturated (11.2-9553 nmol L-1; 440-354 444 %), whereas N2O ranged from strong undersaturation to supersaturation (3.2-20.6 nmol L-1; 47-205 %). Evidently, rivers of the ROC are persistent local sources of CH4 and can be minor sources or sinks for N2O. During the dry season the mean and range of CH4 and N2O concentrations were quite similar for the three land types. Wet and dry season mean concentrations and ranges were not significant for N2O for any land type or for CH4 in savannah rivers. The latter observation is consistent with seasonal buffering of river discharge by an underlying sandstone aquifer. Significantly higher wet season CH4 concentrations in swamp and forest rivers suggest that CH4 can be derived from floating macrophytes during flooding and/or enhanced methanogenesis in adjacent flooded soils. Swamp rivers also exhibited both low (47 %) and high (205 %) N2O saturation but wet season values were overall significantly lower than in either tropical forest or

  13. The Himalaya-Bengal Fan source to sink system - new insights by correlation of re-processed seismic data and IODP Expedition 354 results

    Science.gov (United States)

    Bergmann, Fenna; Schwenk, Tilmann; Spiess, Volkard; France-Lanord, Christian

    2016-04-01

    The Bengal Fan, hosted in the northern Indian Ocean, is the largest submarine fan on Earth. Fan evolution started in the Early Eocene as a direct response to the collision of India with the Asian continent in Middle Paleocene times. Subsequently the Himalayan plateau uplift was initiated. Thereby generated interactions with the regional climate caused the evolution of the Indian monsoonal system. Drained by the rivers Ganges and Brahmaputra, ~ 80% of eroded Himalayan sediments are deposited in the Bengal Fan. Hence, the Fan provides the most complete record of the Himalayan history and is well suited to investigate the direct link between the tectonic uplift and the climate evolution of the region. Sediments are transported onto the deep sea fan by turbidity currents building up chan-nel-levee systems. These channel-levee systems are the main architectural elements of the Bengal Fan and are suspected to have their onset in Late Miocene times. Frequent channel avulsion on the upper fan led to the abandonment of old channels and formation of new channel-levee systems or even channel-reoccupation. This complex erosional/depositional system involves lateral depocenter migration, probably on millennial timescales. Conse-quently, investigations of the Himalaya as sediment source begins with a comprehensive understanding of transport, deposition and modification within the Bengal Fan sediment sink. In February/March 2015 the IODP Expedition 354 drilled at 7 sites along a ~320 km long E-W transect at 8° N. Aiming at the recovery of pre-fan deposits and deposits of the Pliocene and Upper Miocene Fan evolution, three deep sites (900 - 1200 mbsf) were realized. These where complemented by four shallow sites (200-300 mbsf) for a detailed study of the depos-its of the last 1-2 million years, including the latest known channel activities (Holocene times). Several channel-levee systems and inter-channel deposits were drilled, active at different times of Fan evolution. To

  14. Sedimentary Records of Shelf Edge Glaciation: A Young Trough-Mouth Fan on the Gulf of Alaska Yakutat Margin

    Science.gov (United States)

    Swartz, J. M.; Gulick, S. P. S.; Goff, J. A.

    2015-12-01

    The St. Elias Mountains in Southeastern Alaska are an active orogen that host temperate marine glaciers. Here, ice streams advancing across the continental shelf during glacial periods create wide shelf-crossing troughs and deliver large sediment volumes directly to the shelf edge, and from there to the continental slope and the deep sea Surveyor Fan. The continental slope exhibits steep morphology (~10°-30°), controlled by the Transition Fault, a transform boundary between the Yakutat micro-plate and the Pacific plate. Prior statistical analysis of continental slope morphology indicates that these steep initial slope conditions have been modified by proximal sedimentation during repeated glacial advances. Downslope of the Yakutat Sea Valley an incipient trough-mouth fan exists while between the troughs and downslope of the Alsek Sea Valley sediment slope-bypass dominates. Seismic analysis indicates that the Yakutat margin has seen significant slope sedimentation since the intensification of northern hemisphere glaciation ~2.6 Ma, but it is only recently that sufficient sediment supply has existed to overwhelm the steep margin topography and form the young trough-mouth fan. The mid-Pleistocene climate transition at ~1 Ma, and its associated shift from 41Kyr to 100Kyr glacial-interglacial climate cycles, could have potentially allowed sustained ice stream advances to the shelf edge and associated high proximal sedimentation on the continental slope. Integration of seismic data and newly obtained age constraints from recent IODP cores allows for investigation into the timing of Yakutat trough-mouth fan sedimentation and its relation to climate transitions.

  15. Numerical and experimental investigation on aerodynamic performance of small axial flow fan with hollow blade root

    Science.gov (United States)

    Li, Zhang; Jin, Yingzi; Huashu, Dou; Yuzhen, Jin

    2013-10-01

    To reduce the influence of adverse flow conditions at the fan hub and improve fan aerodynamic performance, a modification of conventional axial fan blades with numerical and experimental investigation is presented. Hollow blade root is manufactured near the hub. The numerical and experimental results show that hollow blade root has some effect on the static performance. Static pressure of the modified fan is generally the same with that of the datum fan, while, the efficiency curve of the modified fan has a different trend with that of the datum fan. The highest efficiency of the modified fan is 10% greater than that of the datum fan. The orthogonal experimental results of fan noise show that hollow blade root is a feasible method of reducing fan noise, and the maximum value of noise reduction is about 2 dB. The factors affecting the noise reduction of hollow blade root are in the order of importance as follows: hollow blade margin, hollow blade height and hollow blade width. The much smoother pressure distribution of the modified fan than that of the datum fan is the main mechanism of noise reduction of hollow blade root. The research results will provide the proof of the parameter optimization and the structure design for high performance and low noise small axial fans.

  16. The state of emergency care in Democratic Republic of Congo

    Directory of Open Access Journals (Sweden)

    Luc Malemo Kalisya

    2015-12-01

    Full Text Available The Democratic Republic of Congo (DRC is the second largest country on the African continent with a population of over 70 million. It is also a major crossroad through Africa as it borders nine countries. Unfortunately, the DRC has experienced recurrent political and social instability throughout its history and active fighting is still prevalent today. At least two decades of conflict have devastated the civilian population and collapsed healthcare infrastructure. Life expectancy is low and government expenditure on health per capita remains one of the lowest in the world. Emergency Medicine has not been established as a specialty in the DRC. While the vast majority of hospitals have emergency rooms or salle des urgences, this designation has no agreed upon format and is rarely staffed by doctors or nurses trained in emergency care. Presenting complaints include general and obstetric surgical emergencies as well as respiratory and diarrhoeal illnesses. Most patients present late, in advanced stages of disease or with extreme morbidity, so mortality is high. Epidemics include HIV, cholera, measles, meningitis and other diarrhoeal and respiratory illnesses. Lack of training, lack of equipment and fee-for-service are cited as barriers to care. Pre-hospital care is also not an established specialty. New initiatives to improve emergency care include training Congolese physicians in emergency medicine residencies and medic ranger training within national parks.

  17. Exogenous nitric oxide inhibits Crimean Congo hemorrhagic fever virus.

    Science.gov (United States)

    Simon, M; Falk, K I; Lundkvist, A; Mirazimi, A

    2006-09-01

    Crimean Congo hemorrhagic fever virus (CCHFV) is a geographically widespread pathogen that causes severe hemorrhagic fever with high mortality. Even though one of the main objectives focuses on the progress of antiviral agents, the research on CCHFV is strongly hampered due to its BSL-4 classification. Nitric oxide (NO), a mediator with broad biological effects, has been shown to possess inhibitory properties against various pathogens. The molecule constitutes a component of the innate immunity and serves to assist in the early immunological events where it contributes to clearance of microorganisms. In this study, we investigated the inhibitory properties of exogenous NO on CCHFV. We found that NO had a significant antiviral activity against CCHFV replication. By using the NO-donor S-nitroso-N-acetylpenicillamine (SNAP) we were able to show up to 99% reduction in virion progeny yield. In contrast, 3-morpholinosydnonimine hydrochloride (SIN-1), a peroxynitrite donor, had no significant antiviral activity against CCHFV. Furthermore the expression of viral proteins; the nucleocapsid protein and the glycoprotein, were clearly reduced with increasing concentrations of SNAP. We have also shown that the amount of total vRNA in SNAP-treated cells was reduced by about 50% compared to the controls.

  18. Hepatitis in Patients with Crimean –Congo Hemorrhagic Fever

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    Batool Sharifi-Mood

    2014-04-01

    Full Text Available Background: Crimean–Congo hemorrhagic fever (CCHF is a viral disease and causing approximately 30% fatality rate. Recent studies have been reported that hepatitis in CCHF patients is with high mortality. The aim of this study was to determine the prevalence of hepatitis in the CCHF cases and also detect the mortality rate among patients with hepatitis. Materials and Methods: The present study was conducted in patients with CCHF who were hospitalized in Boo-Ali hospital in Zahedan between Oct 2009 to Feb 2012. Liver function tests including aminotransferase enzymes and prothrombin time and mortality rate were evaluated. Results: Among 53 patients with CCHF, hepatitis was seen in 19 patients (45%. Nine patients died (21%. All dead patients had a serum aminotransaminase level ≥10 times the upper normal limit. Conclusion: Our study showed that hepatitis is prevalent in CCHF patients and a serum aminotransaminase level ≥5 times the upper normal limit (UNL is a risk factor for severe disease and high mortality.

  19. The global distribution of Crimean-Congo hemorrhagic fever

    Science.gov (United States)

    Messina, Jane P.; Pigott, David M.; Golding, Nick; Duda, Kirsten A.; Brownstein, John S.; Weiss, Daniel J.; Gibson, Harry; Robinson, Timothy P.; Gilbert, Marius; William Wint, G. R.; Nuttall, Patricia A.; Gething, Peter W.; Myers, Monica F.; George, Dylan B.; Hay, Simon I.

    2015-01-01

    Background Crimean-Congo hemorrhagic fever (CCHF) is a tick-borne infection caused by a virus (CCHFV) from the Bunyaviridae family. Domestic and wild vertebrates are asymptomatic reservoirs for the virus, putting animal handlers, slaughter-house workers and agricultural labourers at highest risk in endemic areas, with secondary transmission possible through contact with infected blood and other bodily fluids. Human infection is characterized by severe symptoms that often result in death. While it is known that CCHFV transmission is limited to Africa, Asia and Europe, definitive global extents and risk patterns within these limits have not been well described. Methods We used an exhaustive database of human CCHF occurrence records and a niche modeling framework to map the global distribution of risk for human CCHF occurrence. Results A greater proportion of shrub or grass land cover was the most important contributor to our model, which predicts highest levels of risk around the Black Sea, Turkey, and some parts of central Asia. Sub-Saharan Africa shows more focalized areas of risk throughout the Sahel and the Cape region. Conclusions These new risk maps provide a valuable starting point for understanding the zoonotic niche of CCHF, its extent and the risk it poses to humans. PMID:26142451

  20. Ocular pentastomiasis in the Democratic Republic of the Congo.

    Directory of Open Access Journals (Sweden)

    Mihály Sulyok

    2014-07-01

    Full Text Available Ocular pentastomiasis is a rare infection caused by the larval stage of pentastomids, an unusual group of crustacean-related parasites. Zoonotic pentastomids have a distinct geographical distribution and utilize reptiles or canids as final hosts. Recently, an increasing number of human abdominal infections have been reported in Africa, where pentastomiasis is an emerging, though severely neglected, tropical disease. Here we describe four ocular infections caused by pentastomids from the Democratic Republic of the Congo. Two cases underwent surgery and an Armillifer grandis infection was detected by morphological and molecular approaches. Thus far, 15 other cases of ocular pentastomiasis have been reported worldwide. Twelve cases were caused by Armillifer sp., recorded almost exclusively in Africa, where such infections occur as a consequence of hunting and consuming snakes, their final hosts. Seven further cases were caused by Linguatula serrata, a cosmopolitan pentastomid whose final hosts are usually canids. Intraocular infections caused permanent visual damage in 69% and a total loss of vision in 31% of reported cases. In contrast, ocular adnexal cases had a benign clinical course. Further research is required to estimate the burden, therapeutic options and pathogenesis of this neglected disease.

  1. Diet and kwashiorkor: a prospective study from rural DR Congo

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    Hallgeir Kismul

    2014-04-01

    Full Text Available The etiology of kwashiorkor remains enigmatic and longitudinal studies examining potential causes of kwashiorkor are scarce. Using historical, longitudinal study data from the rural area of Bwamanda, Democratic Republic of Congo, we investigated the potential causal association between diet and the development of kwashiorkor in 5 657 preschool children followed 3-monthly during 15 months. We compared dietary risk factors for kwashiorkor with those of marasmus. Kwashiorkor was diagnosed as pitting oedema of the ankles; marasmus as abnormal visibility of skeletal structures and palpable wasting of the gluteus muscle. A 24-h recall was administered 3-monthly to record the consumption of the 41 locally most frequent food items. We specified Hanley–Miettinen smooth-in-time risk models containing potential causal factors, including food items, special meals prepared for the child, breastfeeding, disease status, nutritional status, birth rank, age, season and number of meals. Bayesian Information Criteria identified the most plausible causal model of why some children developed kwashiorkor. In a descriptive analysis of the diet at the last dietary assessment prior to development of kwashiorkor, the diet of children who developed kwashiorkor was characterized by low consumption of sweet potatoes, papaya and “other vegetables” [0.0% , 2.3% (95% CI [0.4, 12.1] and 2.3% (95% CI [0.4, 12.1

  2. Redescriptions of three species of freshwater crabs from the Democratic Republic of Congo, Central Africa (Brachyura: Potamoidea: Potamonautidae).

    Science.gov (United States)

    Cumberlidge, Neil

    2015-06-16

    The taxonomy of three species of freshwater crabs from the Upper Congo River in the Democratic Republic of Congo, Potamonautes congoensis (Rathbun, 1921), P. langi (Rathbun, 1921), and P. stanleyensis (Rathbun, 1921), is revised based on examination of the holotypes. Updated diagnoses, illustrations, and distribution maps are provided for these species, and their conservation status is discussed.

  3. An estimate of the costs of an effective system of protected areas in the Niger Delta - Congo Basin Forest Region

    NARCIS (Netherlands)

    Blom, A.

    2004-01-01

    This paper presents an analysis of the costs of implementing a biodiversity conservation vision for the Niger Delta-Congo Basin Forest Region, a region covering the forests from Nigeria across Cameroon, Equatorial Guinea (EG), Gabon, Central African Republic (CAR), Congo and the Democratic Republic

  4. Fan-structure wave as a source of earthquake instability

    Science.gov (United States)

    Tarasov, Boris

    2015-04-01

    Today frictional shear resistance along pre-existing faults is considered to be the lower limit on rock shear strength at confined compression corresponding to the seismogenic layer. This determines the lithospheric strength and the primary earthquake mechanism associated with frictional stick-slip instability on pre-existing faults. This paper introduces a recently identified shear rupture mechanism providing a paradoxical feature of hard rocks - the possibility of shear rupture propagation through the highly confined intact rock mass at shear stress levels significantly less than frictional strength. In the new mechanism the rock failure, associated with consecutive creation of small slabs (known as 'domino-blocks') from the intact rock in the rupture tip, is driven by a fan-shaped domino structure representing the rupture head. The fan-head combines such unique features as: extremely low shear resistance (below the frictional strength), self-sustaining stress intensification in the rupture tip (providing easy formation of new domino-blocks), and self-unbalancing conditions in the fan-head (making the failure process inevitably spontaneous and violent). An important feature of the fan-mechanism is the fact that for the initial formation of the fan-structure an enhanced local shear stress is required, however, after completion of the fan-structure it can propagate as a dynamic wave through intact rock mass at shear stresses below the frictional strength. Paradoxically low shear strength of pristine rocks provided by the fan-mechanism determines the lower limit of the lithospheric strength and favours the generation of new faults in pristine rocks in preference to frictional stick-slip instability along pre-existing faults. The new approach reveals an alternative role of pre-existing faults in earthquake activity: they represent local stress concentrates in pristine rock adjoining the fault where special conditions for the fan-mechanism nucleation are created

  5. Numerical Study of Transition of an Annular Lift Fan Aircraft

    Directory of Open Access Journals (Sweden)

    Yun Jiang

    2016-09-01

    Full Text Available The present study aimed at studying the transition of annular lift fan aircraft through computational fluid dynamics (CFD simulations. The oscillations of lift and drag, the optimization for the figure of merit, and the characteristics of drag, yawing, rolling and pitching moments in transition are studied. The results show that a two-stage upper and lower fan lift system can generate oscillations of lift and drag in transition, while a single-stage inner and outer fan lift system can eliminate the oscillations. The characteristics of momentum drag of the single-stage fans in transition are similar to that of the two-stage fans, but with the peak of drag lowered from 0.63 to 0.4 of the aircraft weight. The strategy to start transition from a negative angle of attack −21° further reduces the peak of drag to 0.29 of the weight. The strategy also reduces the peak of pitching torque, which needs upward extra thrusts of 0.39 of the weight to eliminate. The peak of rolling moment in transition needs differential upward thrusts of 0.04 of the weight to eliminate. The requirements for extra thrusts in transition lead to a total thrust–weight ratio of 0.7, which makes the aircraft more efficient for high speed cruise flight (higher than 0.7 Ma.

  6. Bifurcation analysis of fan casing under rotating air flow excitation

    Institute of Scientific and Technical Information of China (English)

    温登哲; 陈予恕

    2014-01-01

    A fan casing model of cantilever circular thin shell is constructed based on the geometric characteristics of the thin-walled structure of aero-engine fan casing. According to Donnelly’s shell theory and Hamilton’s principle, the dynamic equations are established. The dynamic behaviors are investigated by a multiple-scale method. The effects of casing geometric parameters and motion parameters on the natural frequency of the system are studied. The transition sets and bifurcation diagrams of the system are obtained through a singularity analysis of the bifurcation equation, showing that various modes of the system such as the bifurcation and hysteresis will appear in different parameter regions. In accordance with the multiple relationship of the fan speed and stator vibration frequency, the fan speed interval with the casing vibration sudden jump is calculated. The dynamic reasons of casing cracks are investigated. The possibility of casing cracking hysteresis interval is analyzed. The results show that cracking is more likely to appear in the hysteresis interval. The research of this paper provides a theoretical basis for fan casing design and system parameter optimization.

  7. Fan Noise Source Diagnostic Test: Vane Unsteady Pressure Results

    Science.gov (United States)

    Envia, Edmane

    2002-01-01

    To investigate the nature of fan outlet guide vane pressure fluctuations and their link to rotor-stator interaction noise, time histories of vane fluctuating pressures were digitally acquired as part of the Fan Noise Source Diagnostic Test. Vane unsteady pressures were measured at seven fan tip speeds for both a radial and a swept vane configuration. Using time-domain averaging and spectral analysis, the blade passing frequency (BPF) harmonic and broadband contents of the vane pressures were individually analyzed. Significant Sound Pressure Level (SPL) reductions were observed for the swept vane relative to the radial vane for the BPF harmonics of vane pressure, but vane broadband reductions due to sweep turned out to be much smaller especially on an average basis. Cross-correlation analysis was used to establish the level of spatial coherence of broadband pressures between different locations on the vane and integral length scales of pressure fluctuations were estimated from these correlations. Two main results of this work are: (1) the average broadband level on the vane (in dB) increases linearly with the fan tip speed for both the radial and swept vanes, and (2) the broadband pressure distribution on the vane is nearly homogeneous and its integral length scale is a monotonically decreasing function of fan tip speed.

  8. Numerical Analysis of Erosion Caused by Biomimetic Axial Fan Blade

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    Jun-Qiu Zhang

    2013-01-01

    Full Text Available Damage caused by erosion has been reported in several industries for a wide range of situations. In the present work, a new method is presented to improve the erosion resistance of machine components by biomimetic method. A numerical investigation of solid particle erosion in the standard and biomimetic configuration blade of axial fan is presented. The analysis consists in the application of the discrete phase model, for modeling the solid particles flow, and the Eulerian conservation equations to the continuous phase. The numerical study employs computational fluid dynamics (CFD software, based on a finite volume method. User-defined function was used to define wear equation. Gas/solid flow axial fan was simulated to calculate the erosion rate of the particles on the fan blades and comparatively analyzed the erosive wear of the smooth surface, the groove-shaped, and convex hull-shaped biomimetic surface axial flow fan blade. The results show that the groove-shaped biomimetic blade antierosion ability is better than that of the other two fan blades. Thoroughly analyze of antierosion mechanism of the biomimetic blade from many factors including the flow velocity contours and flow path lines, impact velocity, impact angle, particle trajectories, and the number of collisions.

  9. Topological invariants of a fan associated to a toric variety

    CERN Document Server

    Ford, T J

    1995-01-01

    Associated to a toric variety X of dimension r over a field k is a fan \\Delta on \\Bbb R^r. The fan \\Delta is a finite set of cones which are in one-to-one correspondence with the orbits of the torus action on X. The fan \\Delta inherits the Zariski topology from X. In this article some cohomological invariants of X are studied in terms of whether or not they depend only on \\Delta and not k. Secondly some numerical invariants of X are studied in terms of whether or not they are topological invariants of the fan \\Delta. That is, whether or not they depend only on the finite topological space defined on \\Delta. The invariants with which we are mostly concerned are the class group of Weil divisors, the Picard group, the Brauer group and the dimensions of the torsion free part of the \\'etale cohomology groups with coefficients in the sheaf of units. The notion of an open neighborhood of a fan is introduced and examples are given for which the above invariants are sufficiently fine to give nontrivial stratifications...

  10. "I'm Buffy, and you're history": Putting fan studies into history [editorial

    Directory of Open Access Journals (Sweden)

    Nancy Reagin

    2011-03-01

    Full Text Available This essay kicks off the special historical issue of Transformative Works and Cultures by offering an overview of the ways in which fan communities have been studied by academic historians, and how fan studies has written the history of fan communities. The essay discusses historical work done by amateur fan historians throughout the 20th century; what academic historians can offer fan communities; why academic historians could benefit from studying fandoms as part of the history of popular culture; and what fan studies as a discipline might gain from a broader historical analysis of fandoms.

  11. Biosorption Kinetic Models on the Removal of Congo red onto Unripe Calamansi (Citrus microcarpa peels

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    Derick Erl P. Sumalapao

    2016-12-01

    Full Text Available Unripe calamansi peels were prepared and used as a bioadsorbent in the removal of congo red from an aqueous solution using batch adsorption studies. The efficiency of adsorption was evaluated by varying adsorbent dose and contact time. The removal of congo red increased at higher adsorbent dose and longer contact time. The overall rate of adsorption processes appeared to be in accordance with the pseudo-second order reaction mechanism. Higher initial adsorption rate, extent of surface coverage, and activation energy were favored at a lower adsorbent dose, while the intraparticle diffusion was relatively faster at a higher adsorbent dose. The intraparticle diffusion, Elovich, and MacArthur-Wilson modelswere adequate in describing the chaotic behavior of the kinetic processes involved in the removal of congo red dye onto unripe calamansi peels.

  12. Rape as a weapon of war in the Democratic Republic of the Congo.

    Science.gov (United States)

    Brown, Carly

    2012-01-01

    The Democratic Republic of the Congo has been appropriately acknowledged as "the rape capital of the world." While the country has been trapped in conflict, the use of rape as a weapon of war has been rampant and unyielding. The sexual violence inflicted upon women has been nothing less than brutal and destructive, physically, socially, and psychologically. This paper analyzes the use of rape as a weapon of war in the Congo, taking into context the ongoing war, cultural and social situations that facilitate its existence, and the many consequences the victims are forced to endure. Drawing information from various academic journals, articles, and field research from international organizations, this paper paints a concise picture of the sexual atrocities occurring in the Democratic Republic of the Congo.

  13. Origins, seasonality, and fluxes of organic matter in the Congo River

    Science.gov (United States)

    Spencer, Robert G. M.; Hernes, Peter J.; Dinga, Bienvenu; Wabakanghanzi, Jose N.; Drake, Travis W.; Six, Johan

    2016-07-01

    The Congo River in central Africa represents a major source of organic matter (OM) to the Atlantic Ocean. This study examined elemental (%OC, %N, and C:N), stable isotopic (δ13C and δ15N), and biomarker composition (lignin phenols) of particulate OM (POM) and dissolved OM (DOM) across the seasonal hydrograph. Even though the Congo exhibits an extremely stable intra-annual discharge regime, seasonal variability in OM composition was evident. DOM appears predominantly derived from vascular plant inputs with greater relative contribution during the rising limb and peak in discharge associated with the major November-December discharge maximum. Generally, POM appears to be sourced from soil-derived mineral-associated OM (low C:N, low Λ8, and higher (Ad:Al)v) but the relative proportion of fresh vascular plant material (higher C:N, higher Λ8, and lower (Ad:Al)v) increases with higher discharge. During the study period (September 2009 to November 2010) the Congo exported 29.21 Tg yr-1 of total suspended sediment (TSS), 1.96 Tg yr-1 of particulate organic carbon (POC), and 12.48 Tg yr-1 of dissolved organic carbon. The Congo exports an order of magnitude lower TSS load in comparison to other major riverine sources of TSS (e.g., Ganges and Brahmaputra), but due to its OM-rich character it actually exports a comparable amount of POC. The Congo is also 2.5 times more efficient at exporting dissolved lignin per unit volume compared to the Amazon. Including Congo dissolved lignin data in residence time calculations for lignin in the Atlantic Ocean results in an approximately 10% reduction from the existing estimate, suggesting that this material is more reactive than previously thought.

  14. Effect of Number of Blades on Performance of Ceiling Fans

    Directory of Open Access Journals (Sweden)

    Adeeb Ehsan

    2015-01-01

    Full Text Available In this paper, the effect of number of blades on ceiling fan performance is discussed. This approach helps to satisfy tradeoff between high air flow (performance and power consumption (energy efficiency. Specifically, variation from two to six blades is considered with nonlinear forward sweep profile. Reynolds Averaged Navier-Stokes (RANS technique is used to model the flow field induced by the ceiling fan inside a generic room. The performance is gauged through response parameters namely volumetric flow rate, mass flow rate, torque and energy efficiency. The results indicate that mass and volumetric flow rates are maximized for six blade configuration and energy efficiency is maximized for two blade configuration. The study indicates the importance of tradeoff between high air flow through ceiling fan and associated energy efficiency.

  15. Performance and Stability Analysis of a Shrouded-Fan UAV

    CERN Document Server

    de Divitiis, Nicola

    2009-01-01

    This paper deals with the estimation of the performance and stability for a shrouded-fan unmanned rotorcraft whose mission profile also prescribes the flight in ground effect. The not so simple estimation of the aerodynamic coefficients and of the thrust in the various situations makes the performance calculation and the stability analysis difficult tasks. This is due to the strong interaction between the fan flow and shroud that causes quite different flow structures about the airframe depending on flight conditions. A further difficulty is related to the ground effect which produces substantial modifications in the rotor thrust and aerodynamic coefficients. To evaluate performance and stability, two models have been developed. One determines the aerodynamic coefficients of the shroud, whereas the other one calculates thrust and moment of the rotors system. Both models take into account the mutual interference between fan flow and fuselage and ground effect. Performance and stability are then discussed with ...

  16. Using Mobile Marketing to Engage NASCAR Fans and Increase Sales

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    MARK DODDS

    2011-01-01

    Full Text Available Mobile marketing displays engage the consumer. This sponsorship activation tactic is highly visible at NASCAR races. Some common elements include show cars, interactive race simulators, video games and race suit/equipment displays. The authors of this study argue that by using mobile marketing effectively as a sponsorship activation tactic, the race fans derive more enjoyment from the race experience. This increased enjoyment links to higher product sales for the sponsor. The implications of this study show that sponsors in other sports should use mobile marketing to increase the fan satisfaction of the game experience in order to increase their product sales. Additionally, event mangers should support mobile marketing as a sponsorship activation tactic with the intention of increasing fan enjoyment and improving attendance.

  17. Particle trajectories and acceleration during 3D fan reconnection

    CERN Document Server

    Dalla, S; 10.1051/0004-6361:200809771

    2008-01-01

    Context. The primary energy release in solar flares is almost certainly due to magnetic reconnection, making this a strong candidate as a mechanism for particle acceleration. While particle acceleration in 2D geometries has been widely studied, investigations in 3D are a recent development. Two main classes of reconnection regimes at a 3D magnetic null point have been identified: fan and spine reconnection Aims. Here we investigate particle trajectories and acceleration during reconnection at a 3D null point, using a test particle numerical code, and compare the efficiency of the fan and spine regimes in generating an energetic particle population. Methods. We calculated the time evolution of the energy spectra. We discuss the geometry of particle escape from the two configurations and characterise the trapped and escaped populations. Results. We find that fan reconnection is less efficent than spine reconnection in providing seed particles to the region of strong electric field where acceleration is possible...

  18. Reflection on Chinese boys' love fans: An insider's view [symposium

    Directory of Open Access Journals (Sweden)

    Erika Junhui Yi

    2013-03-01

    Full Text Available The fandom of BL, as it is known in China, celebrates explicit homoerotic relationships between boys or men—fictional characters taken from mainstream media, real-life celebrities, and male personifications of day-to-day objects and animals, as well as original characters. Mainstream media reports on BL fandom and BL fan girls in China have never been favorable; this subculture and the fans within it are constantly represented in a negative and biased light. But because I am a BL fan girl myself, I can offer an insider's perspective. This essay is a reflection on my personal experiences and observations as a member of BL fandom, and a response to erroneous, stigmatizing claims and moral panic about this community in China.

  19. A velocity parameter for the correlation of axial fan noise

    Science.gov (United States)

    Wright, T.

    1982-08-01

    An aerodynamic parameter that relates subsonic axial fan noise to the fundamental flow behavior in the blade row of a fan is proposed. The parameter is the peak or maximum blade surface velocity in the rotating reference frame and includes, either explicitly or implicitly, the influence of tip speed, volume flow rate, pressure rise, shaft horsepower and efficiency. Correlation of the noise associated with a very broad range of axial fans yields good agreement and collapse of data when compared to currently used correlation methods. Use of this parameter, rather than those based on overall performance, allows trade-off studies to be made within a given performance requirement so that a minimum noise configuration may be designed or selected.

  20. Effect of inlet box on performance of axial flow fans

    Institute of Scientific and Technical Information of China (English)

    Jingyin LI; Hua TIAN; Xiaofang YUAN

    2008-01-01

    Numerical investigations on 3D flow fields in an axial flow fan with and without an inlet box have been extensively conducted, focusing on the variation of fan performance caused by the internal flow fields and the velocity evenness at the exit of the inlet box. It is interest-ing to find that although the inlet box is well designed in accordance with basic design principles, there is a flow separation region in it. Furthermore, this flow separation and the resulting uneven velocity distribution at the exit lead to some decrease in the efficiency and an increase in the total pressure rise of the fan. This research shows that the inlet box needs further improvement and such a check on the flow fields is of value for the design of inlet boxes.

  1. Fan filmmaking and copyright in a global world: Warhammer 40,000 fan films and the case of Damnatus

    Directory of Open Access Journals (Sweden)

    John Walliss

    2010-09-01

    Full Text Available The last decade has witnessed a proliferation, both online and off-line, of films produced by amateurs inspired by mainstream films, TV shows, and novels. As with much other fan production, fan films exist in, at best, a legally gray area since they are produced by amateurs, rather than by the media companies that own the copyrights to the films and novels that provide both their inspiration and settings. I examine the phenomenon of fan filmmaking, focusing on films produced by fans of the Warhammer 40,000 (W40K tabletop battle game. In particular, I examine the case of Damnatus: The Enemy Within (Damnatus: Feind Im Innern, 2005, a German-made fan film set in the W40K universe, which was banned from release by the game's rights holder, the UK company Games Workshop, in 2007. Damnatus offers an interesting case study in both the ongoing struggle between rights holders and textual poachers and the tensions that can exist between different legal understandings of copyright in an increasingly globalized world.

  2. Intraplate compressional deformation in West-Congo and the Congo basin: related to ridge-puch from the South Atlantic spreading ridge?

    Science.gov (United States)

    Delvaux, Damien; Everaerts, Michel; Kongota Isasi, Elvis; Ganza Bamulezi, Gloire

    2016-04-01

    After the break-up and separation of South America from Africa and the initiation of the South-Atlantic mid-oceanic ridge in the Albian, at about 120 Ma, ridge-push forces started to build-up in the oceanic lithosphere and were transmitted to the adjacent continental plates. This is particularly well expressed in the passive margin and continental interior of Central Africa. According to the relations of Wiens and Stein (1985) between ridge-push forces and basal drag in function of the lithospheric age of oceanic plates, the deviatoric stress reaches a compressional maximum between 50 and 100, Ma after the initiation of the spreading ridge, so broadly corresponding to the Paleocene in this case (~70-20 Ma). Earthquake focal mechanism data show that the West-Congo margin and a large part of the Congo basin are still currently under compressional stresses with an horizontal compression parallel to the direction of the active transform fracture zones. We studied the fracture network along the Congo River in Kinshasa and Brazzaville which affect Cambrian sandstones and probably also the late Cretaceous-Paleocene sediments. Their brittle tectonic evolution is compatible with the buildup of ridge-push forces related to the South-Atlantic opening. Further inland, low-angle reverse faults are found affecting Jurassic to Middle Cretaceous cores from the Samba borehole in the Congo basin and strike-slip movements are recorded as a second brittle phase in the Permian cores of the Dekese well, at the southern margin of the Congo basin. An analysis of the topography and river network of the Congo basin show the development of low-amplitude (50-100 m) long wavelengths (100-300 km) undulations that can be interpreted as lithospheric buckling in response to the compressional intraplate stress field generated by the Mid-Atlantic ridge-push. Wiens, D.A., Stein, S., 1985. Implications of oceanic intraplate seismicity for plate stresses, driving forces and theology. Tectonophysics

  3. The Reasonable Explanation of Annihilation (fanā in Mysticism

    Directory of Open Access Journals (Sweden)

    Abulfazel Kiashemshaki

    2012-06-01

    Full Text Available Abstrak : Para mistikus melampaui tahap-tahap (derajat kesempurnaan mistik dan maqam spiritual dalam perjalanan mereka menuju Allah yang sulit dimengerti oleh non-mistikus. Karena itu, sebagian besar kalangan reflektif berusaha mengandalkan prinsip-prinsip intelektual dan teoritis mereka untuk memperoleh penjelasan atas pengalaman mistis dan ekstasi. Namun, keberhasilan penjelasannya sepenuhnya berada di bawah kuasa dan kekuatan dari prinsip-prinsip tersebut. (Fanā atau kesirnaan adalah salah satu tahap mistis atau keadaan yang sulit dimengerti oleh non-mistikus sehingga memunculkan berbagai teori yang berbeda untuk menjelaskannya. Pencapaian prestasi ilmiah dan filosofis merupakan penjelasan yang tepat atas fanā. Bagaimanapun upaya yang dilakukan dalam artikel ini membuktikan bahwa satu-satunya penjelasan yang sukses adalah penjelasan yang didasarkan pada prinsip-prinsip teosofi transendental dan mistisisme teoritis.Kata kunci : Fanā, Mistisisme, Penjelasan rasional, Mistisisme teoretis, Filsafat transendentalAbstract : Mystics are passing through stages (degrees of mystic perfection and esoteric abodes (spiritual stations in their spiritual journey to Allah which is difficult for unmystics to understand. Because of this, most of the reflective people are trying to rely on their intellectual and theoretical principles to obtain an understandable explanation of mystical experiences and ecstasy. However the success of such explanation completely lies in the power and strength of the above mentioned principles. (Fanā or annihilation is one of the mystical stages or states which unmystics find very difficult to reasonably understand, hence various and different theories have been provided for its explanation. Various scientific and philosophical achievements are appropriate explanations of annihilation (fanā which is valuable in its place; however effort had been made in this article to prove that the only successful explanation is an

  4. ADSORPTION OF CONGO RED DYE ON HAZELNUT SHELLS AND DEGRADATION WITH Phanerochaete chrysosporium

    Directory of Open Access Journals (Sweden)

    Riccardo A. Carletto

    2008-11-01

    Full Text Available The present work concerns the experimental evaluation of hazelnut shells as a low cost natural biosorbent. Adsorption of the direct azo dye Congo Red was performed within a concentrations range of 50-5000 mg/L. Hazelnut shells were employed as organic support for Phanerochaete chrysosporium cultures to study the best cultural medium composition for the MnP production. The capability of Phanerochaete chrysosporium to take macronutrients as carbon and nitrogen from hazelnut shells was demonstrated. Cultures of Phanerochaete chrysosporium were carried out with hazelnut shells coming from Congo Red adsorption tests, showing that 43% of the adsorbed dye was degraded.

  5. [Sexual violence in Congo-Kinshasa: necessity of decriminalizing abortion].

    Science.gov (United States)

    Kalonda, J C Omba

    2012-01-01

    The sexual violence's committed in the Democratic Republic of Congo (DRC) are from their scales and consequences on women, real public health, politico-legal, and socio-economical challenges. More than a million of women have been victims of sexual violence on a period of less than fifteen years. Systematic rapes of women were used as war weapon by different groups involved in the Congolese war. Sexual violence against women has impacted public health by spreading sexually transmissible diseases including HIV/AIDS, causing unwanted pregnancies, leading to the gynaecological complications of rape-related injuries, and inflicting psychological trauma on the victims. Despite high level of unwanted pregnancies observed, the Congolese law is very restrictive and interdict induced abortion. This paper presents three arguments which plead in favour of legalizing abortion in DRC: 1) a restrictive law on abortion forces women to use unsafe abortion and increase incidence of injuries and maternal mortality ; 2) DRC has ratified the universal Declaration of human rights, the African union charter, and has than to promote equality between sexes, in this is included women reproductive rights; 3) an unwanted birth is an additional financial charge for a woman, a factor increasing poverty and psychologically unacceptable in case of rape. From the politico-legal point of view, ending rape impunity and decriminalizing abortion are recommended. Decriminalizing abortion give women choice and save victims and pregnant women from risks related to the pregnancy, a childbirth, or an eventual unsafe abortion. These risks increase the maternal mortality already high in DRC (between 950 and 3000 for 100000 live births).

  6. Vectors of Crimean Congo Hemorrhagic Fever Virus in Iran

    Directory of Open Access Journals (Sweden)

    Zakkyeh Telmadarraiy

    2015-10-01

    Full Text Available Background: Ticks are important vectors and reservoirs of Crimean Congo Hemorrhagic Fever (CCHF virus. Human beings may be infected whenever the normal life cycle of the infected ticks on non- human vertebrate hosts is interrupted by the undesirable presence of humans in the cycle. A total of 26 species of Argasid and Ixodid ticks have been recorded in Iran; including nine Hyalomma, two Rhipicephalus, two Dermacentor, five Haemaphysalis, two Boophilus, one Ixodes and two Argas as well as three Ornithodoros species as blood sucking ectoparasites of livestock and poultries. The present paper reviews tick vectors of CCHF virus in Iran, focusing on the role of ticks in different provinces of Iran using reverse transcription polymerase chain reaction (RT-PCR assay.Methods: During ten years study, 1054 tick specimens; including two species of Argasidae and 17 species of Ixodidae were examined for their infection to CCHF virus genome. The output of all studies as well as related publications were discussed in the current paper.Results: The results show that Rhipicephalus sanguineus, Hyalomma marginatum, H. anatolicum, H. asiaticum and H. dromedarii were known as the most frequent species which were positive for CCHF virus.Conclusion: The status of ticks which were positive for CCHF virus revealed that unlike the most common idea that Hyalomma species are the most important vectors of CCHF virus, other ticks including Rhipicephalus,Haemaphysalis and Dermacentor can be reservoir of this virus; thus, considering geographical distribution, type of host and environmental conditions, different tick control measurements should be carried out in areas with high incidence of CCHF disease.

  7. The Boundary Layer Interaction with Shock Wave and Expansion Fan

    Institute of Scientific and Technical Information of China (English)

    MaratA.Goldfeld; RomanV.Nestoulia; 等

    2000-01-01

    The results of experimental investigation of a turbulent boundary layer on compression and expansion surfaces are presented.They include the study of the shock wave and /or expansion fan action upon the boundary layer,boundary layer sepqartion and its relaxation.Complex events of paired interactions and the flow on compression convex-concave surfaces were studied.The posibility and conditions of the boundary layer relaminarization behind the expansion fan and its effect on the relaxation length are presented.Different model configurations for wide range conditions were investigated.Comparison of results for different interactions was carried out.

  8. Novel stator design of fan motors using soft magnetic composites

    Science.gov (United States)

    Hsu, Yu-Sheng; Tsai, Mi-Ching; Hsieh, Min-Fu

    2008-04-01

    Cooling fans are an important device needed in consumer electronic products. To enhance the performance of cooling fans, this paper presents a novel brushless dc motor with a three dimensional stator structure using soft magnetic composite to reduce the hub size and allow more airflow. Four models are designed and their output characteristics are compared using finite element simulation. From the results, one of them is selected for prototyping whose performance appears to meet the requirement. The prototype has a 10% smaller diameter than that of conventional types. Moreover, the operation test shows that the required performance is achieved.

  9. On a Fixed Point Theorem of Ky Fan

    Institute of Scientific and Technical Information of China (English)

    DE BLASI Francesco S.; GEORGIEV Pando Gr.

    2002-01-01

    We generalize a theorem of Ky Fan about the nearest distance between a closed convex setD in a Banach space E and its image by a function f: D → E, in several directions: (1) for noncompactsets D, when f(D) precompact; (2) for compact D and upper semicontinuous multifunction f; andmore generally, (3) for noncompact D and upper semicontinuous multifunction f with f(D) Hausdorffprecompact.In particular, we prove a version of the fixed point theorem of Kakutani-Ky Fan for multifunctions,whose values are convex closed bounded, thus not necessarily compact.

  10. Supersonic stall flutter of high-speed fans

    Science.gov (United States)

    Adamczyk, J. J.; Stevans, W.; Jutras, R.

    1981-01-01

    An analytical model is proposed for predicting the onset of supersonic stall bending flutter in high-speed rotors. The analysis is based on a modified two-dimensional, compressible, unsteady actuator disk theory. The stability boundary predicted by the analysis is shown to be in good agreement with the measured boundary of a high speed fan. The prediction that the flutter mode would be a forward traveling wave sensitive to wheel speed and aerodynamic loading is confirmed by experimental measurements. In addition, the analysis shows that reduced frequency and dynamic head also play a significant role in establishing the supersonic stall bending flutter boundary of an unshrouded fan.

  11. The Female Vikings, a women's fan group in Denmark

    DEFF Research Database (Denmark)

    Mintert, Svenja-Maria; Pfister, Gertrud Ursula

    2014-01-01

    Traditionally, football and fandom have been male domains and celebrations of masculinity. So far there has been some sociological and historical research on women's football; however, little is known about women's fandom, in particular about its formation and development. This article focuses...... on the historical development of a Danish women-only fan group called 'The Female Vikings', which support a professional football club, Lyngby Boldklub (BK), in a city north of Copenhagen. The article explores the backgrounds and motivations of female fans, as well as their ways of staging femininity in a man...

  12. The Female Vikings, a women's fan group in Denmark

    DEFF Research Database (Denmark)

    Mintert, Svenja-Maria; Pfister, Gertrud Ursula

    2014-01-01

    Traditionally, football and fandom have been male domains and celebrations of masculinity. So far there has been some sociological and historical research on women's football; however, little is known about women's fandom, in particular about its formation and development. This article focuses......'s world. Drawing on available information about football and fans in Denmark, we have reconstructed the developments of both Lyngby BK and its supporters. Special focus was placed on the histories and cultures as well as the experiences of female fans in this club. Insights into the foundation...

  13. Performance evaluation methods and instrumentation for mine ventilation fans

    Institute of Scientific and Technical Information of China (English)

    LI Man; WANG Xue-rong

    2009-01-01

    Ventilation fans are one of the most important pieces of equipment in coal mines. Their performance plays an important role in the safety of staff and production. Given the actual requirements of coal mine production, we instituted a research project on the measurement methods of key performance parameters such as wind pressure, amount of ventilation and power. At the end a virtual instrument for mine ventilation fans performance evaluation was developed using a USB interface. The practical perform-ance and analytical results of our experiments show that it is feasible, reliable and effective to use the proposed instrumentation for mine ventilation performance evaluation.

  14. "Cultural acupuncture": Fan activism and the Harry Potter Alliance

    Directory of Open Access Journals (Sweden)

    Henry Jenkins

    2012-06-01

    Full Text Available Fan activists have struggled to defend series from cancellation, defend themselves from cease and desist orders, promote alternative representations, and raise money for charity. Building on this background, this article examines how the Harry Potter Alliance encourages young people to speak out as fans on a broad range of human rights and social justice issues through what the group's leader, Andrew Slack, calls "cultural acupuncture." The group's practice of mapping the fictional content world onto real-world concerns helps empower young people to become civicly engaged and politically active.

  15. Towards a three-component model of fan loyalty: a case study of Chinese youth.

    Science.gov (United States)

    Zhang, Xiao-xiao; Liu, Li; Zhao, Xian; Zheng, Jian; Yang, Meng; Zhang, Ji-qi

    2015-01-01

    The term "fan loyalty" refers to the loyalty felt and expressed by a fan towards the object of his/her fanaticism in both everyday and academic discourses. However, much of the literature on fan loyalty has paid little attention to the topic from the perspective of youth pop culture. The present study explored the meaning of fan loyalty in the context of China. Data were collected by the method of in-depth interviews with 16 young Chinese people aged between 19 and 25 years who currently or once were pop fans. The results indicated that fan loyalty entails three components: involvement, satisfaction, and affiliation. These three components regulate the process of fan loyalty development, which can be divided into four stages: inception, upgrade, zenith, and decline. This model provides a conceptual explanation of why and how young Chinese fans are loyal to their favorite stars. The implications of the findings are discussed.

  16. ON A KIND OF GENERALIZED QUASI-VARIATIONAL INEQUALITIES AND FAN's MINIMAX INEQUALITY WITHOUT CONVEXITY

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    This paper gives a Fan,s type minimax theorem, a nearst point theorem and two existence theorems of solutions for a kind of generalized quasi-variational inequalities in H-spaces without any linear structure.

  17. Towards a three-component model of fan loyalty: a case study of Chinese youth.

    Directory of Open Access Journals (Sweden)

    Xiao-xiao Zhang

    Full Text Available The term "fan loyalty" refers to the loyalty felt and expressed by a fan towards the object of his/her fanaticism in both everyday and academic discourses. However, much of the literature on fan loyalty has paid little attention to the topic from the perspective of youth pop culture. The present study explored the meaning of fan loyalty in the context of China. Data were collected by the method of in-depth interviews with 16 young Chinese people aged between 19 and 25 years who currently or once were pop fans. The results indicated that fan loyalty entails three components: involvement, satisfaction, and affiliation. These three components regulate the process of fan loyalty development, which can be divided into four stages: inception, upgrade, zenith, and decline. This model provides a conceptual explanation of why and how young Chinese fans are loyal to their favorite stars. The implications of the findings are discussed.

  18. Experimental investigation of the noise emission of axial fans under distorted inflow conditions

    Science.gov (United States)

    Zenger, Florian J.; Renz, Andreas; Becher, Marcus; Becker, Stefan

    2016-11-01

    An experimental investigation on the noise emission of axial fans under distorted inflow conditions was conducted. Three fans with forward-skewed fan blades and three fans with backward-skewed fan blades and a common operating point were designed with a 2D element blade method. Two approaches were adopted to modify the inflow conditions: first, the inflow turbulence intensity was increased by two different rectangular grids and second, the inflow velocity profile was changed to an asymmetric characteristic by two grids with a distinct bar stacking. An increase in the inflow turbulence intensity affects both tonal and broadband noise, whereas a non-uniform velocity profile at the inlet influences mainly tonal components. The magnitude of this effect is not the same for all fans but is dependent on the blade skew. The impact is greater for the forward-skewed fans than for the backward-skewed and thus directly linked to the fan blade geometry.

  19. Design and Research of Intelligent Remote Control Fan Based on Single Chip Microcomputer and Bluetooth Technology

    National Research Council Canada - National Science Library

    Xue-Xia Zhang; You-Yun Dang; An-Ying Fu

    2017-01-01

    This paper is designed for intelligent remote control fans. The design of the microcontroller as the core, the sensor, Bluetooth and Andrews system applied to the design of intelligent remote control fan...

  20. Process sedimentology of submarine fan deposits - new perspectives

    Science.gov (United States)

    Postma, George

    2017-04-01

    To link submarine fan process sedimentology with sand distribution, sand body architecture, texture and fabric, the field geologist studies sedimentary facies, facies associations (fan elements) and stratigraphy. Facies analysis resides on factual knowledge of modern fan morphodynamics and physical modelling of en-masse sediment transport. Where do we stand after 55 years of submarine research, i.e. the date when the first submarine fan model was launched by Arnold Bouma in 1962? Since that date students of submarine fans have worked on a number of important, recurring questions concerned with facies analysis of submarine successions in outcrop and core: 1. What type of sediment transport produced the beds? 2. What facies can be related to initial flow conditions? 3. What is the significance of grain size jumps and bounding surface hierarchy in beds consisting of crude and spaced stratification (traction carpets)? Do these point to multi flow events or to flow pulsations by one and the same event? 4. What facies associations relate to the basic elements of submarine fans? 5. What are the autogenic and allogenic signatures in submarine fans? Particularly in the last decade, the enormous technical advancement helped to obtain high-quality data from observations of density flows in modern canyons, deep basins and deep-water delta slopes (refs 1,2,3). In combination with both physical (refs 4,5) and numerical modelling (ref 6) these studies broke new ground into our understanding of density flow processes in various submarine environments and have led to new concepts of submarine fan building by super- and subcritical high-density flow (ref 7). Do these new concepts provide better answers to our recurrent questions related to the morphodynamics of submarine fans and prediction of sand body architecture? In discussing this open question, I shall 1. apply the new concepts to a modern and ancient example of a channel-lobe-transition-zone (ref 8); 2. raise the problem of

  1. A Critical Review of Computational Methods and Their Application in Industrial Fan Design

    OpenAIRE

    Alessandro Corsini; Giovanni Delibra; Sheard, Anthony G.

    2013-01-01

    Members of the aerospace fan community have systematically developed computational methods over the last five decades. The complexity of the developed methods and the difficulty associated with their practical application ensured that, although commercial computational codes date back to the 1980s, they were not fully exploited by industrial fan designers until the beginning of the 2000s. The application of commercial codes proved to be problematic as, unlike aerospace fans, industrial fans i...

  2. Debris-flow dominance of alluvial fans masked by runoff reworking and weathering.

    OpenAIRE

    Haas, T.; Ventra, D.; Carbonneau, P. E.; Kleinhans, M. G.

    2014-01-01

    Arid alluvial fan aggradation is highly episodic and fans often comprise active and inactive sectors. Hence the morphology and texture of fan surfaces are partly determined by secondary processes of weathering and erosion in addition to primary processes of aggradation. This introduces considerable uncertainty in the identification of formative processes of terrestrial and Martian fans from aerial and satellite imagery. The objectives of this study are (i) to develop a model to describe the s...

  3. A secondary source configuration for control of a ventilation fan noise in ducts

    OpenAIRE

    Čudina, Mirko; Prezelj, Jurij

    2015-01-01

    The main noise source in heating, ventilation, and air conditioning systems is usually a ventilating fan. Noise, generated by the ventilating fan is transmitted through the duct into the living and working environment. A typical fan noise spectrum consists of a broadband noise, which is superimposed with pure tones. Different methods are available to reduce a transmission of such noise from the ventilating fan into the living and working environment. In this article it is demonstrated how a f...

  4. Late Holocene geomorphic record of fire in ponderosa pine and mixed-conifer forests, Kendrick Mountain, northern Arizona, USA

    Science.gov (United States)

    Sara E. Jenkins; Carolyn Hull Sieg; Diana E. Anderson; Darrell S. Kaufman; Philip A. Pearthree

    2011-01-01

    Long-term fire history reconstructions enhance our understanding of fire behaviour and associated geomorphic hazards in forested ecosystems. We used 14C ages on charcoal from fire-induced debris-flow deposits to date prehistoric fires on Kendrick Mountain, northern Arizona, USA. Fire-related debris-flow sedimentation dominates Holocene fan deposition in the study area...

  5. Surface morphology of fans in the high-Arctic periglacial environment of Svalbard : Controls and processes

    NARCIS (Netherlands)

    De Haas, Tjalling; Kleinhans, Maarten G.; Carbonneau, Patrice E.; Rubensdotter, Lena; Hauber, Ernst

    2015-01-01

    Fan-shaped landforms occur in all climatic regions on Earth. They have been extensively studied in many of these regions, but there are few studies on fans in periglacial, Arctic and Antarctic regions. Fans in such regions are exposed to many site-specific environmental conditions in addition to the

  6. 30 CFR 75.313 - Main mine fan stoppage with persons underground.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Main mine fan stoppage with persons underground... COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Ventilation § 75.313 Main mine fan stoppage with persons underground. (a) If a main mine fan stops while anyone is underground...

  7. Debris-flow dominance of alluvial fans masked by runoff reworking and weathering

    NARCIS (Netherlands)

    de Haas, Tjalling; Ventra, Dario; Carbonneau, Patrice E.; Kleinhans, Maarten G.

    2014-01-01

    Arid alluvial fan aggradation is highly episodic and fans often comprise active and inactive sectors. Hence the morphology and texture of fan surfaces are partly determined by secondary processes of weathering and erosion in addition to primary processes of aggradation. This introduces considerable

  8. Evaluation of sugar-cane bagasse as bioadsorbent in the textile wastewater treatment contaminated with carcinogenic congo red dye

    Directory of Open Access Journals (Sweden)

    Aline Sartório Raymundo

    2010-08-01

    Full Text Available A methodology involving sugar cane bagasse bioadsorbent was developed in order to remove the carcinogenic congo red dye from aqueous medium. The results showed high efficiency with retention of 64 ± 6% in synthetic congo red solution and 94 ± 5% in effluent enriched with congo red, at 10.0 g of the bioadsorbent. The adsorption system provided a maximum adsorption capacity of 4.43 mg/g. Tests showed independence adsorption properties, when compared with the column flow rates. The treatment units could be operated with flexibility. From the results, it was possible to conclude that sugar cane bagasse could be an adequate bioadsorbent.Neste trabalho foi desenvolvida uma metodologia de remoção do corante carcinogênico congo red de sistemas aquosos. Os resultados mostraram uma elevada eficiência de remoção sendo de 64 ± 6% para soluções sintéticas de vermelho congo, e 94 ± 5% para efluente industrial enriquecido com vermelho congo utilizando 10 g de bioadsorvente. A capacidade máxima adsotiva encontrada foi de 4,43 mg/g. Os testes de percolação revelaram independência das porcentagens adsortivas em relação às vazões das colunas. Estes resultados indicam viabilidade de uso do bagaço de cana-de-açucar no tratamento de efluentes contendo o congo red.

  9. Palaeoflow reconstruction from fan delta morphology on Mars

    NARCIS (Netherlands)

    Kleinhans, M.G.; Kasteele, H.E. van de; Hauber, E.

    2010-01-01

    Alluvial fans and deltas on Mars record past hydrological conditions. Until now these conditions have been inferred from the morphology of the feeder channels and the deposits from images and digital terrain models (DTMs), and from calculations of the bulk fluxes of water and sediment based on the d

  10. KKM and KY fan theorems in modular function spaces

    Directory of Open Access Journals (Sweden)

    Latif Abdul

    2011-01-01

    Full Text Available Abstract In modular function spaces, we introduce Knaster-Kuratowski-Mazurkiewicz mappings (in short KKM-mappings and prove an analogue to Ky Fan s fixed point theorem. 2010 Mathematics Subject Classification: Primary 46B20, 47H09; Secondary 47H10.

  11. The Nonrelativistic Scattering States of the Deng-Fan Potential

    Directory of Open Access Journals (Sweden)

    Bentol Hoda Yazarloo

    2013-01-01

    Full Text Available The approximately analytical scattering state solution of the Schrodinger equation is obtained for the Deng-Fan potential by using an approximation scheme to the centrifugal term. Energy eigenvalues, normalized wave functions, and scattering phase shifts are calculated. We consider and verify two special cases: the l=0 and the s-wave Hulthén potential.

  12. Modeling Fan Effects on the Time Course of Associative Recognition

    Science.gov (United States)

    Schneider, Darryl W.; Anderson, John R.

    2012-01-01

    We investigated the time course of associative recognition using the response signal procedure, whereby a stimulus is presented and followed after a variable lag by a signal indicating that an immediate response is required. More specifically, we examined the effects of associative fan (the number of associations that an item has with other items…

  13. Investigation of Cross Flow Fan Propulsion for Lightweight VTOL Aircraft

    Science.gov (United States)

    2000-12-01

    the aircraft longitudinal axis due to the total length of the unit. A total fan span of 20.6 inches is required to produce 690 lbf of thrust when...which are mounted parallel to the aircraft longitudinal axis and rest perpendicular, would be actuated as required to provide yaw control and aft

  14. Studying a Spacecraft Ventilation Fan: Progress and Possibilities

    Science.gov (United States)

    Koch, L. Denielle

    2011-01-01

    This document describes a presentation delivered to the Acoustics Technical Working Group at a meeting held in Cleveland, Ohio on April 21-22, 2011. The information contained in this presentation is considered to be preliminary, intended to begin a general discussion among audience members on the challenges associated with spacecraft ventilation fans and possible avenues of continued research.

  15. Propellers And Fans Based On The Moebius Strip

    Science.gov (United States)

    Seiner, John Milton; Gilinsky, Mikhail Markovich

    1996-01-01

    Moebius strip proposed as basis for optimally shaped airplane and boat propellers, fans, helicopter rotors, mixing screws, coffee grinders, and concrete mixers. Basic idea of optimal shaping of such device to increase working efficiency by increasing area for capture of still medium without increasing power needed for rotation.

  16. Intermittent Flow Regimes in a Transonic Fan Airfoil Cascade

    Directory of Open Access Journals (Sweden)

    J. Lepicovsky

    2004-01-01

    velocity.To date, this flow behavior has only been observed in a linear transonic cascade. Further research is necessary to confirm this phenomenon occurs in actual transonic fans and is not the by-product of an endwall restricted linear cascade.

  17. Energy efficient engine shroudless, hollow fan blade technology report

    Science.gov (United States)

    Michael, C. J.

    1981-01-01

    The Shroudless, Hollow Fan Blade Technology program was structured to support the design, fabrication, and subsequent evaluation of advanced hollow and shroudless blades for the Energy Efficient Engine fan component. Rockwell International was initially selected to produce hollow airfoil specimens employing the superplastic forming/diffusion bonding (SPF/DB) fabrication technique. Rockwell demonstrated that a titanium hollow structure could be fabricated utilizing SPF/DB manufacturing methods. However, some problems such as sharp internal cavity radii and unsatisfactory secondary bonding of the edge and root details prevented production of the required quantity of fatigue test specimens. Subsequently, TRW was selected to (1) produce hollow airfoil test specimens utilizing a laminate-core/hot isostatic press/diffusion bond approach, and (2) manufacture full-size hollow prototype fan blades utilizing the technology that evolved from the specimen fabrication effort. TRW established elements of blade design and defined laminate-core/hot isostatic press/diffusion bonding fabrication techniques to produce test specimens. This fabrication technology was utilized to produce full size hollow fan blades in which the HIP'ed parts were cambered/twisted/isothermally forged, finish machined, and delivered to Pratt & Whitney Aircraft and NASA for further evaluation.

  18. SOME GENERALIZATIONS OF KY FAN'S BEST APPROXIMATION THEOREM

    Institute of Scientific and Technical Information of China (English)

    A.R.Khan; N.Hussain; A.B.Thaheem

    2004-01-01

    We pressent new Ky Fan type best approximation theorems for a discontinuous multivalued map on metrizable topological vector spaces and hyperconvex spaces. In addition, fixed point results are derived for the map studied. Our work generalizes severl results in approximation theory.

  19. Così fan tutte: Brilliance or Buffoonery?

    Directory of Open Access Journals (Sweden)

    Sarah Whitfield

    2011-12-01

    Full Text Available Hardly any opera has endured more scrutiny and self-preserving apology than Mozart’s Così fan tutte. Flagrant opposition and a long string of “rescue” attempts shroud the receptive history of the work. Since its premiere, Così fan tutte has long been recognized as a problem opera. Many critics found it implausible that Mozart—the consummate composer and man that warranted their idolization—could have stooped so low as to agree to such an immoral plot. The great beauty in Mozart’s musical parody is that it at once mocks and transforms the supposed superficial experiment of Lorenzo Da Ponte’s libretto. The parody in Così fan tutte must be correctly interpreted. It is rampant, but it exists for much more than a perfunctory laugh. The beauty of Mozart’s music—in both moments of wild parody and heartfelt emotion—succeeds in giving Così fan tutte a depth that is both challenging and transforming.

  20. Analysis and control of computer cooling fan noise

    Science.gov (United States)

    Wong, Kam

    This thesis is divided into three parts: the study of the source mechanisms and their separation, passive noise control, and active noise control. The mechanisms of noise radiated by a typical computer cooling fan is investigated both theoretically and experimentally focusing on the dominant rotor-stator interaction. The unsteady force generated by the aerodynamic interaction between the rotor blades and struts is phase locked with the blade rotation and radiates tonal noise. Experimentally, synchronous averaging with the rotation signal extracts the tones made by the deterministic part of the rotor-strut interaction mechanism. This averaged signal is called the rotary noise. The difference between the overall noise and rotary noise is defined as random noise which is broadband in the spectrum. The deterministic tonal peaks are certainly more annoying than the broadband, so the suppression of the tones is the focus of this study. Based on the theoretical study of point force formulation, methods are devised to separate the noise radiated by the two components of drag and thrust forces on blades and struts. The source separation is also extended to the leading and higher order modes of the spinning pressure pattern. By using the original fan rotor and installing it in various casings, the noise sources of the original fan are decomposed into elementary sources through directivity measurements. Details of the acoustical directivity for the original fan and its various modifications are interpreted. For the sample fan, two common features account for most of the tonal noise radiated. The two features are the inlet flow distortion caused by the square fan casing, and the large strut carrying the electric wires for the motor. When the inlet bellmouth is installed and the large strut is trimmed down to size, a significant reduction of 12 dB in tonal sound power is achieved. These structural corrections constitute the passive noise control. However, the end product still

  1. First Test of Fan Active Noise Control (ANC) Completed

    Science.gov (United States)

    2005-01-01

    With the advent of ultrahigh-bypass engines, the space available for passive acoustic treatment is becoming more limited, whereas noise regulations are becoming more stringent. Active noise control (ANC) holds promise as a solution to this problem. It uses secondary (added) noise sources to reduce or eliminate the offending noise radiation. The first active noise control test on the low-speed fan test bed was a General Electric Company system designed to control either the exhaust or inlet fan tone. This system consists of a "ring source," an induct array of error microphones, and a control computer. Fan tone noise propagates in a duct in the form of spinning waves. These waves are detected by the microphone array, and the computer identifies their spinning structure. The computer then controls the "ring source" to generate waves that have the same spinning structure and amplitude, but 180 out of phase with the fan noise. This computer generated tone cancels the fan tone before it radiates from the duct and is heard in the far field. The "ring source" used in these tests is a cylindrical array of 16 flat-plate acoustic radiators that are driven by thin piezoceramic sheets bonded to their back surfaces. The resulting source can produce spinning waves up to mode 7 at levels high enough to cancel the fan tone. The control software is flexible enough to work on spinning mode orders from -6 to 6. In this test, the fan was configured to produce a tone of order 6. The complete modal (spinning and radial) structure of the tones was measured with two builtin sets of rotating microphone rakes. These rakes provide a measurement of the system performance independent from the control system error microphones. In addition, the far-field noise was measured with a semicircular array of 28 microphones. This test represents the first in a series of tests that demonstrate different active noise control concepts, each on a progressively more complicated modal structure. The tests are

  2. European survey on laboratory preparedness, response and diagnostic capacity for crimean-congo haemorrhagic fever, 2012

    NARCIS (Netherlands)

    M.D. Fernandez-Garcia (Maria Dolores); A. Negredo; A. Papa (Anna); O. Donoso-Mantke; M. Niedrig; H. Zeller; A. Tenorio; L. Franco (Leticia); S.W. Aberle (Stephan W.); M. van Esbroeck (M.); I. Christova; A. Markotic (Alemka); I.-C. Kurolt (Ivan-Christian); H. Zelena (Hana); I. Golovljova; D. Pannetier (Delphine); R. Charrel (Remi); J. Schmidt-Chanasit (Jonas); R. Wölfel (Roman); A. Papa (Anna); M.R. Capobianchi (Maria Rosaria); X. Jakupi (Xhevat); J. Storozenko (Jelena); A. Griskevicius (Algis); G. Bosevska (Golubinka); C. Muscat (Clive); M. Schutten (Martin); S.G. Dudman (Susanne Gjeruldsen); M.J. Alves (M. João); C.S. Ceianu; A. Platonov (Alexander); B. Bozovic (Bojana); B. Klempa; T. Avsic (Tatjana); A. Tenorio; Å. Lundkvist (Åke); P. Cherpillod (Pascal); G. Korukluoglu; D.W.G. Brown (D. W G); T. Brooks (Tim)

    2014-01-01

    textabstractCrimean-Congo haemorrhagic fever (CCHF) is an infectious viral disease that has (re-)emerged in the last decade in south-eastern Europe, and there is a risk for further geographical expansion to western Europe. Here we report the results of a survey covering 28 countries, conducted in 20

  3. Colonial Exploitation and Economic Development: The Belgian Congo and the Netherlands Indies Compared

    NARCIS (Netherlands)

    Frankema, E.H.P.; Buelens, F.

    2013-01-01

    This volume discusses the comparative legacy of colonial rule in the Netherlands Indies and Belgian Congo during the nineteenth and twentieth centuries. Whereas the Indonesian economy progressed rapidly during the last three decades of the twentieth century and became a self-reliant and assertive

  4. Nosocomial infection of Crimean-Congo haemorrhagic fever in eastern Iran: case report.

    Science.gov (United States)

    Chinikar, Sadegh; Shayesteh, Majid; Khakifirouz, Sahar; Jalali, Tahmineh; Rasi Varaie, Fereshteh Sadat; Rafigh, Mahboubeh; Mostafavi, Ehsan; Shah-Hosseini, Nariman

    2013-01-01

    An outbreak of Crimean-Congo haemorrhagic fever occurred in the county of Birjand in eastern Iran in November 2011. Four cases were involved in this outbreak. Two patients died after admission to hospital, one of whom was a nurse who acquired the infection nosocomially, and the others were treated successfully.

  5. An outbreak of West Nile fever among migrants in Kisangani, Democratic Republic of Congo

    NARCIS (Netherlands)

    Y.A. Nur; J. Groen (Jan); H. Heuvelmans; W. Tuynman; C. Copra (Cederick); A.D.M.E. Osterhaus (Albert)

    1999-01-01

    textabstractIn February 1998, an outbreak of acute febrile illness was reported from the Kapalata military camp in Kisangani, the Democratic Republic of Congo. The illness was characterized by an acute onset of fever associated with severe headache, arthralgia, backache, neurologic

  6. An outbreak of West Nile fever among migrants in Kisangani, Democratic Republic of Congo.

    NARCIS (Netherlands)

    Y.A. Nur; J. Groen (Jan); H. Heuvelmans; W. Tuynman; C. Copra (Cederick); A.D.M.E. Osterhaus (Albert)

    1999-01-01

    textabstractIn February 1998, an outbreak of acute febrile illness was reported from the Kapalata military camp in Kisangani, the Democratic Republic of Congo. The illness was characterized by an acute onset of fever associated with severe headache, arthralgia, backache, neurologic signs, abdominal

  7. Institutional aspects of artisanal mining in forest landscapes, western Congo Basin

    NARCIS (Netherlands)

    Schure, J.; Ingram, V.; Tieguhong, J.C.; Ndikumagenge, C.; Runge, J.; Shikwati, J.

    2011-01-01

    This contribution examines the multiple impacts of artisanal mining in the high-biodiversity forest of the Congo Basin’s Sangha Tri-National Landscape (TNS), and proposes measures for improving livelihoods in the area. It was concluded from a literature review, interviews and site visits that: diamo

  8. A model to predict when a cholera outbreak might hit the Congo

    Science.gov (United States)

    Schultz, Colin

    2014-09-01

    In 2011, as many as 600,000 people in 58 countries contracted cholera, with thousands succumbing to the disease. In most countries, cholera is rare. In others, like the Democratic Republic of the Congo, cholera is an endemic threat, always lurking in the background waiting for the right set of conditions to spark an outbreak.

  9. Phytochemical analysis and biological evaluation of selected African propolis samples from Cameroon and Congo

    NARCIS (Netherlands)

    Papachroni, D.; Graikou, K.; Kosalec, I.; Damianakos, H.; Ingram, V.J.; Chinou, I.

    2015-01-01

    The objective of this study was the chemical analysis of four selected samples of African propolis (Congo and Cameroon) and their biological evaluation. Twenty-one secondary metabolites belonging to four different chemical groups were isolated from the 70% ethanolic extracts of propolis and their st

  10. Severe Crimean-Congo haemorrhagic fever presented with massive retroperitoneal haemorrhage that recovered without antiviral treatment

    DEFF Research Database (Denmark)

    Gharabaghi, Mehrnaz Asadi; Chinikar, Sadegh; Ghiasi, Seyyed Mojtaba

    2011-01-01

    Crimean-Congo haemorrhagic fever (CCHF) is a tickborne viral zoonosis with up to 50% mortality in humans caused by CCHF virus belonging to the genus Nairovirus, family Bunyaviridae. The geographical distribution of CCHF cases corresponds closely with the distribution of principle tick vectors...

  11. A case report of crimean congo hemorrhagic Fever in ostriches in iran

    DEFF Research Database (Denmark)

    Mostafavi, Ehsan; Chinikar, Sadegh; Moradi, Maryam

    2013-01-01

    Crimean Congo hemorrhagic fever (CCHF) is a viral zoonosis, which is usually transmitted via tick bites or close contact with infected blood or tissue. This disease can cause a case fatality rate of up to 25%-30% in humans. CCHF Infection in birds is less documented. An ostrich can reproduce...

  12. African Swine Fever Virus p72 Genotype IX in Domestic Pigs, Congo, 2009

    Science.gov (United States)

    Anchuelo, Raquel; Pelayo, Virginia; Poudevigne, Frédéric; Leon, Tati; Nzoussi, Jacques; Bishop, Richard; Pérez, Covadonga; Soler, Alejandro; Nieto, Raquel; Martín, Hilario; Arias, Marisa

    2011-01-01

    African swine fever virus p72 genotype IX, associated with outbreaks in eastern Africa, is cocirculating in the Republic of the Congo with West African genotype I. Data suggest that viruses from eastern Africa are moving into western Africa, increasing the threat of outbreaks caused by novel viruses in this region. PMID:21801650

  13. Ethnicity, Education, and Fertility Transition in Kinshasa, Congo. Working Paper 2-97-1. Revised.

    Science.gov (United States)

    Shapiro, David; Tambashe, B. Oleko

    Substantial ethnic differences in fertility were documented in the Congo in the mid-1950s. These differences, apparent as well among women residing in Kinshasa, the capital, were linked to variations across ethnic groups in the incidence of venereal diseases and sterility. By the mid-1970s ethnic differences in fertility had diminished but were…

  14. Antimicrobial Drug Resistance of Vibrio cholerae, Democratic Republic of the Congo.

    Science.gov (United States)

    Miwanda, Berthe; Moore, Sandra; Muyembe, Jean-Jacques; Nguefack-Tsague, Georges; Kabangwa, Ickel Kakongo; Ndjakani, Daniel Yassa; Mutreja, Ankur; Thomson, Nicholas; Thefenne, Helene; Garnotel, Eric; Tshapenda, Gaston; Kakongo, Denis Kandolo; Kalambayi, Guy; Piarroux, Renaud

    2015-05-01

    We analyzed 1,093 Vibrio cholerae isolates from the Democratic Republic of the Congo during 1997-2012 and found increasing antimicrobial drug resistance over time. Our study also demonstrated that the 2011-2012 epidemic was caused by an El Tor variant clonal complex with a single antimicrobial drug susceptibility profile.

  15. The context and dynamics of the war in Congo-Kinshasa since ...

    African Journals Online (AJOL)

    Much of the weakness of the state structures to implement policies was related to ... features of the rule of Mobutu included no clear distinction between public and private .... However, Western countries, the World Bank and the International Monetary Fund began .... Kabila as the new ruler of Congo-Kinshasa in May 1997.

  16. Discoloration of Congo Red by Rod-Plate Dielectric Barrier Discharge Processes at Atmospheric Pressure

    Science.gov (United States)

    Wu, Haixia; Fang, Zhi; Zhou, Tong; Lu, Chen; Xu, Yanhua

    2016-05-01

    A dielectric barrier discharge (DBD) reactor with a rod-plate electrode configuration was used for the oxidative decomposition of Congo red dye in an aqueous solution. Plasma was generated in the gas space above the water interface under atmospheric pressure. Discharge characteristics were analyzed by voltage-current waveforms. Effects of applied voltage, initial conductivity, and initial concentration were also analyzed. Congo red discoloration increased with increased applied voltage and decreased conductivity. The initial conductivity significantly influenced the Congo red discoloration. Under the same conditions, the highest discoloration rate was obtained at 25 mg/L. The presence of ferrous ions in the solutions had a substantial positive effect on Fenton dye degradation and flocculation. At an applied voltage of 20 kV, about 100% of dye was degraded after 4 min of Fe2+/DBD treatment. Results showed that adding a certain dosage of hydrogen peroxide to the wastewater could enhance the discoloration rate. Possible pathways of Congo red discoloration by DBD plasma were proposed based on GC/MS, FTIR, and UV-vis spectroscopy analyses. supported by National Natural Science Foundation of China (No. 51377075), the Natural Science Foundation of Jiangsu Province of China (Nos. BK20131412, BK20150951)

  17. Discoloration of Congo Red by Rod-Plate Dielectric Barrier Discharge Processes at Atmospheric Pressure

    Institute of Scientific and Technical Information of China (English)

    WU Haixia; FANG Zhi; ZHOU Tong; LU Chen; XU Yanhua

    2016-01-01

    A dielectric barrier discharge (DBD) reactor with a rod-plate electrode configuration was used for the oxidative decomposition of Congo red dye in an aqueous solution.Plasma was generated in the gas space above the water interface under atmospheric pressure.Discharge characteristics were analyzed by voltage-current waveforms.Effects of applied voltage,initial conductivity,and initial concentration were also analyzed.Congo red discoloration increased with increased applied voltage and decreased conductivity.The initial conductivity significantly influenced the Congo red discoloration.Under the same conditions,the highest discoloration rate was obtained at 25 mg/L.The presence of ferrous ions in the solutions had a substantial positive effect on Fenton dye degradation and flocculation.At an applied voltage of 20 kV,about 100%of dye was degraded after 4 min of Fe2+/DBD treatment.Results showed that adding a certain dosage of hydrogen peroxide to the wastewater could enhance the discoloration rate.Possible pathways of Congo red discoloration by DBD plasma were proposed based on GC/MS,FTIR,and UV-vis spectroscopy analyses.

  18. Democratic Republic of Congo Reforming the Public Service Wage System : Background Paper

    OpenAIRE

    World Bank

    2008-01-01

    The civil service management model in the Demorcatic Republic of Congo (DRC) still conforms to the old institutional order. The legislation governing employment in the public sector is unchanged and still responds to centralized administration. The public administration categorizes public employees in two main groups: civil servants and local public employees. Civil servants are governed b...

  19. "New Education" for the Congo? The Indigenist Approach, New Education and Prescriptive Pedagogy

    Science.gov (United States)

    Depaepe, Marc; Simon, Frank; Vinck, Honoré

    2015-01-01

    This article responds to a question put forward approximately a decade ago by the history of education research group at the Katholieke Universiteit Leuven: Did the child-centred ideas of New Education, as promoted by Ovide Decroly, influence the education policy in the former Belgian colony of Congo? Naturally, ideas were circulating that could…

  20. Mapping monkeypox transmission risk through time and space in the Congo Basin

    Science.gov (United States)

    Nakazawa, Yoshinori J.; Lash, R. Ryan; Carroll, Darin S.; Damon, Inger K.; Karem, Kevin L.; Reynolds, Mary G.; Osorio, Jorge E.; Rocke, Tonie E.; Malekani, Jean; Muyembe, Jean-Jacques; Formenty, Pierre; Peterson, A. Townsend

    2013-01-01

    Monkeypox is a major public health concern in the Congo Basin area, with changing patterns of human case occurrences reported in recent years. Whether this trend results from better surveillance and detection methods, reduced proportions of vaccinated vs. non-vaccinated human populations, or changing environmental conditions remains unclear. Our objective is to examine potential correlations between environment and transmission of monkeypox events in the Congo Basin. We created ecological niche models based on human cases reported in the Congo Basin by the World Health Organization at the end of the smallpox eradication campaign, in relation to remotely-sensed Normalized Difference Vegetation Index datasets from the same time period. These models predicted independent spatial subsets of monkeypox occurrences with high confidence; models were then projected onto parallel environmental datasets for the 2000s to create present-day monkeypox suitability maps. Recent trends in human monkeypox infection are associated with broad environmental changes across the Congo Basin. Our results demonstrate that ecological niche models provide useful tools for identification of areas suitable for transmission, even for poorly-known diseases like monkeypox.

  1. African Swine Fever Virus p72 Genotype IX in Domestic Pigs, Congo, 2009

    OpenAIRE

    2011-01-01

    African swine fever virus p72 genotype IX, associated with outbreaks in eastern Africa, is cocirculating in the Republic of the Congo with West African genotype I. Data suggest that viruses from eastern Africa are moving into western Africa, increasing the threat of outbreaks caused by novel viruses in this region.

  2. African swine fever virus p72 genotype IX in domestic pigs, Congo, 2009.

    Science.gov (United States)

    Gallardo, Carmina; Anchuelo, Raquel; Pelayo, Virginia; Poudevigne, Frédéric; Leon, Tati; Nzoussi, Jacques; Bishop, Richard; Pérez, Covadonga; Soler, Alejandro; Nieto, Raquel; Martín, Hilario; Arias, Marisa

    2011-08-01

    African swine fever virus p72 genotype IX, associated with outbreaks in eastern Africa, is cocirculating in the Republic of the Congo with West African genotype I. Data suggest that viruses from eastern Africa are moving into western Africa, increasing the threat of outbreaks caused by novel viruses in this region.

  3. Scorpion envenomation in pygmies from Democratic Republic of Congo, the example of Pelenge Center, Lomela, DRC

    Directory of Open Access Journals (Sweden)

    E Biezakala Mudiandambu

    2012-01-01

    Full Text Available In a survey among the pygmies of central Democratic Republic of Congo, the incidence of scorpion stings seemed very high with a severity greater than expected. Species responsible were not identified. Specific studies are needed to clarify the risk emerging in the equatorial African forest.

  4. Phytochemical analysis and biological evaluation of selected African propolis samples from Cameroon and Congo

    NARCIS (Netherlands)

    Papachroni, D.; Graikou, K.; Kosalec, I.; Damianakos, H.; Ingram, V.J.; Chinou, I.

    2015-01-01

    The objective of this study was the chemical analysis of four selected samples of African propolis (Congo and Cameroon) and their biological evaluation. Twenty-one secondary metabolites belonging to four different chemical groups were isolated from the 70% ethanolic extracts of propolis and their

  5. Genetic detection and isolation of crimean-congo hemorrhagic fever virus, Kosovo, Yugoslavia.

    Science.gov (United States)

    Papa, Anna; Bozovi, Bojana; Pavlidou, Vassiliki; Papadimitriou, Evangelia; Pelemis, Mijomir; Antoniadis, Aantonis

    2002-08-01

    Crimean-Congo hemorrhagic fever virus (C-CHFV) strains were isolated from a fatal case and the attending physician in Kosovo, Yugoslavia. Early, rapid diagnosis of the disease was achieved by reverse transcription-polymerase chain reaction. The physician was successfully treated with oral ribavirin. These cases yielded the first genetically studied C-CHFV human isolates in the Balkans.

  6. Outgassing from the Congo River Basin: a Major Source of Atmospheric CH4

    Science.gov (United States)

    Salter, M. E.; Mann, P. J.; Dinga, B.; Poulsen, J.; Barnes, J.; Fiske, G.; Upstill-Goddard, R. C.; Holmes, R. M.

    2011-12-01

    Methane (CH4) is a major greenhouse gas and although its production by human activities now exceeds that by natural sources, the single largest source in the global CH4 budget is natural production in wetlands. Recent studies have highlighted the potential importance of tropical regions as a significant source of tropospheric CH4 although large uncertainties remain. A major part of the uncertainty is that many important source regions remain at best only poorly investigated. One such region is the Congo River basin. Although recent satellite-derived measurements have highlighted the potentially large contribution of the Congo basin (25.7 ± 1.7 Tg CH4 y-1) to overall wetland emissions, political instability and limited infrastructure have severely inhibited in situ sampling of this region. Here we report surface water measurements of dissolved methane from a range of streams and rivers throughout a ˜ 260,600 km2 quadrant of the low-gradient central Congo basin collected in November 2010 and August 2011. We estimated regional CH4 emissions by partitioning the basin into distinct landcover types using satellite-derived estimates of seasonal water coverage and land-cover type. Scaling-up these estimates, we demonstrate that the Congo River basin, and in particular its wetland regions, are a globally significant atmospheric source of CH4. These wetland regions are now under threat from deforestation and degradation, highlighting the critical need for improved regional CH4 budgets to inform future policy decisions within the region.

  7. Há uma luz no coração das trevas? Guerra e paz no Congo

    Directory of Open Access Journals (Sweden)

    Wolfgang Döpcke

    2011-09-01

    Full Text Available A partir de uma análise do livro “Coração das Trevas”, de Joseph Conrad, o presente artigo busca delinear as principais características da calamitosa situação vivida pela República do Congo.

  8. Salmonella typhi in the democratic republic of the congo: fluoroquinolone decreased susceptibility on the rise.

    Directory of Open Access Journals (Sweden)

    Octavie Lunguya

    Full Text Available BACKGROUND: Drug resistance of Salmonella enterica serovar Typhi (Salmonella Typhi to first-line antibiotics is emerging in Central Africa. Although increased use of fluoroquinolones is associated with spread of resistance, Salmonella Typhi with decreased ciprofloxacin susceptibility (DCS has rarely been reported in Central Africa. METHODOLOGY/PRINCIPAL FINDINGS: As part of a microbiological surveillance study in the Democratic Republic of the Congo (DR Congo, Salmonella Typhi isolates from bloodstream infections were collected prospectively between 2007 and 2011. The genetic relationship of the Salmonella Typhi isolates was assessed by pulsed-field gel electrophoresis (PFGE. The antimicrobial resistance profile of the isolates was determined and mutations associated with DCS were studied. In total, 201 Salmonella Typhi isolates were collected. More than half of the Salmonella Typhi isolates originated from children and young adults aged 5-19. Thirty different PFGE profiles were identified, with 72% of the isolates showing a single profile. Multidrug resistance, DCS and azithromycin resistance were 30.3%, 15.4% and 1.0%, respectively. DCS was associated with point mutations in the gyrA gene at codons 83 and 87. CONCLUSIONS/SIGNIFICANCE: Our study describes the first report of widespread multidrug resistance and DCS among Salmonella Typhi isolates from DR Congo. Our findings highlight the need for increased microbiological diagnosis and surveillance in DR Congo, being a prerequisite for rational use of antimicrobials and the development of standard treatment guidelines.

  9. Phytochemical analysis and biological evaluation of selected African propolis samples from Cameroon and Congo

    NARCIS (Netherlands)

    Papachroni, D.; Graikou, K.; Kosalec, I.; Damianakos, H.; Ingram, V.J.; Chinou, I.

    2015-01-01

    The objective of this study was the chemical analysis of four selected samples of African propolis (Congo and Cameroon) and their biological evaluation. Twenty-one secondary metabolites belonging to four different chemical groups were isolated from the 70% ethanolic extracts of propolis and their st

  10. Surveillance and laboratory detection system of Crimean-Congo haemorrhagic fever in Iran

    DEFF Research Database (Denmark)

    Chinikar, S; Goya, M M; Shirzadi, M R

    2008-01-01

    be spread from person to person and is one of the rare haemorrhagic fever viruses able to cause nosocomial outbreaks in hospitals. Crimean-Congo haemorrhagic fever is a public health problem in many regions of the world such as Eastern Europe, Asia, the Middle East and Africa. In addition to clinical...

  11. Managing Water Resource Challenges in the Congo River Basin

    Science.gov (United States)

    Aloysius, N. R.

    2015-12-01

    Water resources in the tropical regions are under pressure from human appropriation and climate change. Current understanding of interactions between hydrology and climate in the tropical regions is inadequate. This is particularly true for the Congo River Basin (CRB), which also lacks hydroclimate data. Global climate models (GCM) show limited skills in simulating CRB's climate, and their future projections vary widely. Yet, GCMs provide the most credible scenarios of future climate, based upon which changes in water resources can be predicted with coupled hydrological models. The objectives of my work are to i) elucidate the spatial and temporal variability of water resources by developing a spatially explicit hydrological model suitable for describing key processes and fluxes, ii) evaluate the performance of GCMs in simulating precipitation and temperature and iii) develop a set of climate change scenarios for the basin. In addition, I also quantify the risks and reliabilities in smallholder rain-fed agriculture and demonstrates how available water resources can be utilized to increase crop yields. Key processes and fluxes of CRB's hydrological cycle are amply characterized by the hydrology model. Climate change projections are evaluated using a multi-model ensemble approach under different greenhouse gas emission scenarios. The near-term projections of climate and hydrological fluxes are not affected by emission scenarios. However, towards the mid-21st century, projections are emission scenario dependent. Available freshwater resources are projected to increase in the CRB, except in the semiarid southeast. These increases present new opportunities and challenges for augmenting human appropriation of water resources. By evaluating agricultural water requirements, and timing and availability of precipitation, I challenge the conventional wisdom that low agriculture productivities in the CRB are primarily attributable to nutrient limitation. Results show that

  12. Experimental Evaluation of Installed Cooking Exhaust Fan Performance

    Energy Technology Data Exchange (ETDEWEB)

    Singer, Brett C.; Delp, William W.; Apte, Michael G.

    2010-11-01

    The installed performance of cooking exhaust fans was evaluated through residential field experiments conducted on a sample of 15 devices varying in design and other characteristics. The sample included two rear downdraft systems, two under-cabinet microwave over range (MOR) units, three different installations of an under-cabinet model with grease screens across the bottom and no capture hood, two devices with grease screens covering the bottom of a large capture hood (one under-cabinet, one wall-mount chimney), four under-cabinet open hoods, and two open hoods with chimney mounts over islands. Performance assessment included measurement of airflow and sound levels across fan settings and experiments to quantify the contemporaneous capture efficiency for the exhaust generated by natural gas cooking burners.Capture efficiency is defined as the fraction of generated pollutants that are removed through the exhaust and thus not available for inhalation of household occupants. Capture efficiency (CE) was assessed for various configurations of burner use (e.g., single front, single back, combination of one front and one back, oven) and fan speed setting. Measured airflow rates were substantially lower than the levels noted in product literature for many of the units. This shortfall was observed for several units costing in excess of $1000. Capture efficiency varied widely (from<5percent to roughly 100percent) across devices and across conditions for some devices. As expected, higher capture efficiencies were achieved with higher fan settings and the associated higher air flow rates. In most cases, capture efficiencies were substantially higher for rear burners than for front burners. The best and most consistent performance was observed for open hoods that covered all cooktop burners and operated at higher airflow rates. The lowest capture efficiencies were measured when a front burner was used with a rear backdraft system or with lowest fan setting for above the range

  13. Design of a Low Speed Fan Stage for Noise Suppression

    Science.gov (United States)

    Dalton, W. N.; Elliot, D. B.; Nickols, K. L.

    1999-01-01

    This report describes the design of a low tip speed, moderate pressure rise fan stage for demonstration of noise reduction concepts. The fan rotor is a fixed-pitch configuration delivering a design pressure ratio of 1.378 at a specific flow of 43.1 lbm/sec/sq ft. Four exit stator configurations were provided to demonstrate the effectiveness of circumferential and axial sweep in reducing rotor-stator interaction tone noise. The fan stage design was combined with an axisymmetric inlet, conical convergent nozzle, and nacelle to form a powered fan-nacelle subscale model. This model has a 22-inch cylindrical flow path and employs a rotor with a 0.30 hub-to-tip radius ratio. The design is fully compatible with an existing NASA force balance and rig drive system. The stage aerodynamic and structural design is described in detail. Three-dimensional (3-D) computational fluid dynamics (CFD) tools were used to define optimum airfoil sections for both the rotor and stators. A fan noise predictive system developed by Pratt & Whitney under contract to NASA was used to determine the acoustic characteristics of the various stator configurations. Parameters varied included rotor-to-stator spacing and vane leading edge sweep. The structural analysis of the rotor and stator are described herein. An integral blade and disk configuration was selected for the rotor. Analysis confirmed adequate low cycle fatigue life, vibratory endurance strength, and aeroelastic suitability. A unique load carrying stator arrangement was selected to minimize generation of tonal noise due to sources other than rotor-stator interaction. Analysis of all static structural components demonstrated adequate strength, fatigue life, and vibratory characteristics.

  14. Evaluation of sugar-cane bagasse as bioadsorbent in the textile wastewater treatment contaminated with carcinogenic congo red dye

    OpenAIRE

    Aline Sartório Raymundo; Romina Zanarotto; Marciela Belisário; Madson de Godoi Pereira; Joselito Nardy Ribeiro; Araceli Verónica Flores Nardy Ribeiro

    2010-01-01

    A methodology involving sugar cane bagasse bioadsorbent was developed in order to remove the carcinogenic congo red dye from aqueous medium. The results showed high efficiency with retention of 64 ± 6% in synthetic congo red solution and 94 ± 5% in effluent enriched with congo red, at 10.0 g of the bioadsorbent. The adsorption system provided a maximum adsorption capacity of 4.43 mg/g. Tests showed independence adsorption properties, when compared with the column flow rates. The treatment uni...

  15. A pilot study of a family focused, psychosocial intervention with war-exposed youth at risk of attack and abduction in north-eastern Democratic Republic of Congo.

    Science.gov (United States)

    O'Callaghan, Paul; Branham, Lindsay; Shannon, Ciarán; Betancourt, Theresa S; Dempster, Martin; McMullen, John

    2014-07-01

    Rural communities in the Haut-Uele Province of northern Democratic Republic of Congo live in constant danger of attack and/or abduction by units of the Lord's Resistance Army operating in the region. This pilot study sought to develop and evaluate a community-participative psychosocial intervention involving life skills and relaxation training and Mobile Cinema screenings with this war-affected population living under current threat. 159 war-affected children and young people (aged 7-18) from the villages of Kiliwa and Li-May in north-eastern DR Congo took part in this study. In total, 22% of participants had been abduction previously while 73% had a family member abducted. Symptoms of post-traumatic stress reactions, internalising problems, conduct problems and pro-social behaviour were assessed by blinded interviewers at pre- and post-intervention and at 3-month follow-up. Participants were randomised (with an accompanying caregiver) to 8 sessions of a group-based, community-participative, psychosocial intervention (n=79) carried out by supervised local, lay facilitators or a wait-list control group (n=80). Average seminar attendance rates were high: 88% for participants and 84% for caregivers. Drop-out was low: 97% of participants were assessed at post-intervention and 88% at 3 month follow-up. At post-test, participants reported significantly fewer symptoms of post-traumatic stress reactions compared to controls (Cohen's d=0.40). At 3 month follow up, large improvements in internalising symptoms and moderate improvements in pro-social scores were reported, with caregivers noting a moderate to large decline in conduct problems among the young people. Trial Registration clinicalTrials.gov, Identifier: NCT01542398.

  16. The Congo Trap: MONUSCO Islands of Stability in the Sea of Instability

    Directory of Open Access Journals (Sweden)

    Alberto Barrera

    2015-11-01

    Full Text Available 2014 was a hopeful year for the Democratic Republic of Congo (DRC. The M23 movement had been defeated in military operations in which one of the last peacekeeping experiments, the UN Force Intervention Brigade, had played a decisive role. A third UN stabilization plan, the ‘islands of stability’ was proposed to continue the stabilization of a country considered in a post-conflict phase. However, the number of internally displaced persons (IDPs has almost tripled in the country since 2007. This article will argue that DRC is still immersed into an old social conflict that existed before the Congo Wars and the roots of which are not being addressed. It will argue that the United Nations Organization Stabilization Mission in the Democratic Republic of the Congo (MONUSCO and the ‘islands of stability’ strategy can address some of the secondary causes of the Congo conflict, such as its internationalization, the presence in DRC of foreign armed groups or the ‘blood minerals’, but cannot address its primary causes: land struggles, an old cycle of violence and the fragmentation of the Congolese society and political elite that is jeopardizing the restoration of the state authority. The huge dimensions of each of these factors make the Congo conflict ‘one of the most complex and intricate environments ever faced by a peacekeeping mission’, for which MONUSCO’s mandate, resources and stabilization strategy do not seem powerful enough. When the UN organized the 2006 elections legitimized a ‘spoiler state’, the bottleneck of all the reforms needed to stabilize the country. The UN fell thus into a trap and became part of the conflict. Lessons learned should be taken for future UN operations.

  17. The Marinoan 17O depletion (MOSD) event: New data from northern Baltica

    Science.gov (United States)

    Rice, A. Hugh N.; Bao, Huiming; Pen, Yongbo

    2017-04-01

    The occurrence of sedimentary barite crystal fans during the aftermath of Marinoan glaciation at 635 million years ago (Ma) has been recognized as a global phenomenon. They have been found so far in South China, West Africa, Laurentia, and Central Australia. Their uniqueness is not only reflected in their morphological features, which appear to have occurred only once in the entire Earth's sedimentary record, but also their non-mass-dependently 17O-depleted oxygen isotope compositions that have provided the strongest support to an ultra-high pCO2 post-Marinoan atmosphere and therefore the Snowball Earth theory. The proposed formation model for the barite fans is that they formed in shallow oceans relatively close to the continent where sulfate influx from oxidative weathering was a significant component and where deep water upwelling brought Ba2+. Here we present an example from East Finnmark, in N. Norway, that also supports this formation model, but with a set of distinctive paleogeographic, sedimentary, and stable isotope features. While growing on or inside cavities of a horizontally deposited cap carbonates in most other sites, barite fans grew either directly on a very uneven end-Cryogenian glaciated crystalline Archean basement surface or on a few centimeters of post-glacial Nyborg Formation sediments in northern Baltica block in today's East Finnmark. The fans have been found occurring only in the Ruossoaivi-Lappaluokoaivi area, immediately west of Varangerfjord; they have not been found at any other outcrops of the Smalfjord or Nyborg formations. Deposition was likely in a tidal or very shallow marine environment. Fans are generally less than 2 cm thick, lie within a dominantly carbonate matrix and are, in some cases, overlain by sandstones. No direct relationships between the barite fans and the cap dolostone have been found. Analysis of 10 samples gave Δ17O values ranging from -0.36‰ to - 1.08‰. The northern Baltica barite fans are probably the

  18. Fans and their applications in General Topology, Functional Analysis and Topological Algebra

    OpenAIRE

    Banakh, Taras

    2016-01-01

    A family of closed subsets of a topological space $X$ is called a (strict) $Cld$-fan in $X$ if this family is (strictly) compact-finite but not locally finite in $X$. Applications of (strict) $Cld$-fans are based on a simple observation that $k$-spaces contain no $Cld$-fan and Ascoli spaces contain no strict $Cld$-fan. In this paper we develop the machinery of (strict) fans and apply it to detecting the $k$-space and Ascoli properties in spaces that naturally appear in General Topology, Funct...

  19. Numerical investigation of geometric parameter effects on the aerodynamic performance of a Bladeless fan

    OpenAIRE

    Mohammad Jafari; Hossein Afshin; Bijan Farhanieh; Atta Sojoudi

    2016-01-01

    Aerodynamic performance of a Bladeless fan is numerically investigated considering the effect of five geometric parameters. Airflow through this fan was analyzed by simulating a Bladeless fan within a 2 m × 2 m × 4 m room. Analysis of the flow field inside the fan and the evaluation of its performance were obtained by solving conservations of mass and momentum equations for the aerodynamic investigations. In order to design the Bladeless fan an Eppler 473 airfoil profile was used as the cross...

  20. Reverse Flow Engine Core Having a Ducted Fan with Integrated Secondary Flow Blades

    Science.gov (United States)

    Kisska, Michael K. (Inventor); Princen, Norman H. (Inventor); Kuehn, Mark S. (Inventor); Cosentino, Gary B. (Inventor)

    2014-01-01

    Secondary air flow is provided for a ducted fan having a reverse flow turbine engine core driving a fan blisk. The fan blisk incorporates a set of thrust fan blades extending from an outer hub and a set of integral secondary flow blades extending intermediate an inner hub and the outer hub. A nacelle provides an outer flow duct for the thrust fan blades and a secondary flow duct carries flow from the integral secondary flow blades as cooling air for components of the reverse flow turbine engine.

  1. On the design and structural analysis of jet engine fan blade structures

    Science.gov (United States)

    Amoo, Leye M.

    2013-07-01

    Progress in the design and structural analysis of commercial jet engine fan blades is reviewed and presented. This article is motivated by the key role fan blades play in the performance of advanced gas turbine jet engines. The fundamentals of the associated physics are emphasized. Recent developments and advancements have led to an increase and improvement in fan blade structural durability, stability and reliability. This article is intended as a high level review of the fan blade environment and current state of structural design to aid further research in developing new and innovative fan blade technologies.

  2. Gas Turbine Engine Having Fan Rotor Driven by Turbine Exhaust and with a Bypass

    Science.gov (United States)

    Suciu, Gabriel L. (Inventor); Chandler, Jesse M. (Inventor)

    2016-01-01

    A gas turbine engine has a core engine incorporating a core engine turbine. A fan rotor is driven by a fan rotor turbine. The fan rotor turbine is in the path of gases downstream from the core engine turbine. A bypass door is moveable from a closed position at which the gases from the core engine turbine pass over the fan rotor turbine, and moveable to a bypass position at which the gases are directed away from the fan rotor turbine. An aircraft is also disclosed.

  3. On-chip grating coupler array on the SOI platform for fan-in/fan-out of MCFs with low insertion loss and crosstalk

    DEFF Research Database (Denmark)

    Ding, Yunhong; Ye, Feihong; Peucheret, Christophe

    2015-01-01

    We report the design and fabrication of a compact multi-core fiber fan-in/fan-out using a grating coupler array on the SOI platform. The grating couplers are fully-etched, enabling the whole circuit to be fabricated in a single lithography and etching step. Thanks to the apodized design for the g......We report the design and fabrication of a compact multi-core fiber fan-in/fan-out using a grating coupler array on the SOI platform. The grating couplers are fully-etched, enabling the whole circuit to be fabricated in a single lithography and etching step. Thanks to the apodized design...

  4. The presence of Praomys, Lophuromys, and Deomys species (Muridae, Mammalia) in the forest blocks separated by the Congo River and its tributaries (Kisangani region, Democratic Republic of Congo)

    DEFF Research Database (Denmark)

    Katuala, Pionus G B; Kennis, Jan; Nicolas, Violaine

    2008-01-01

    that the importance of the rivers as a barrier differs for the studied species. For example, P. misonnei was only collected from the right bank of the Congo, while P. lukolelae appears to be restricted to the left bank. In contrast, Praomys identified as P. mutoni or as members of the P. jacksoni species complex...... are collected on both sides of the Congo River. In contrast, all Lophuromys species were collected in a limited number of sampling sites only. L. dudui and L. luteogaster were only collected along the right bank of the Congo River, and the latter species appears to be restricted to the right bank of the Lindi...... that are either separated by the Congo River or its tributaries. A total of 42,466 trapping nights resulted in the collection of 1185 Praomys, 233 Lophuromys and 209 Deomys ferrugineus. We observed that in almost all cases the studied species appear to have restricted distribution ranges, and that it is likely...

  5. Aeroelastic Calculations of Quiet High- Speed Fan Performed

    Science.gov (United States)

    Bakhle, Milind A.; Srivastava, Rakesh; Mehmed, Oral; Min, James B.

    2002-01-01

    An advanced high-speed fan was recently designed under a cooperative effort between the NASA Glenn Research Center and Honeywell Engines & Systems. The principal design goals were to improve performance and to reduce fan noise at takeoff. Scale models of the Quiet High-Speed Fan were tested for operability, performance, and acoustics. During testing, the fan showed significantly improved noise characteristics, but a self-excited aeroelastic vibration known as flutter was encountered in the operating range. Flutter calculations were carried out for the Quiet High-Speed Fan using a three-dimensional, unsteady aerodynamic, Reynolds-averaged Navier-Stokes turbomachinery code named "TURBO." The TURBO code can accurately model the viscous flow effects that can play an important role in various aeroelastic problems such as flutter with flow separation, flutter at high loading conditions near the stall line (stall flutter), and flutter in the presence of shock and boundary-layer interaction. Initially, calculations were performed with no blade vibrations. These calculations were at a constant rotational speed and a varying mass flow rate. The mass flow rate was varied by changing the backpressure at the exit boundary of the computational domain. These initial steady calculations were followed by aeroelastic calculations in which the blades were prescribed to vibrate harmonically in a natural mode, at a natural frequency, and with a fixed interblade phase angle between adjacent blades. The AE-prep preprocessor was used to interpolate the in-vacuum mode shapes from the structural dynamics mesh onto the computational fluid dynamics mesh and to smoothly propagate the grid deformations from the blade surface to the interior points of the grid. The aeroelastic calculations provided the unsteady aerodynamic forces on the blade surface due to blade vibrations. These forces were vector multiplied with the structural dynamic mode shape to calculate the work done on the blade during

  6. Quantitative analysis of the geometry of submarine channels: Implications for the classification of submarine fans

    Science.gov (United States)

    Clark, J. D.; Kenyon, N. H.; Pickering, K. T.

    1992-07-01

    Certain attributes of submarine channels measured from GLORIA sidescan sonar data from 16 different submarine fans indicate similarities with fluviatile systems. Channel width, depth, meander radius and wavelength, sinuosity, and gradient were measured. This approach makes it possible to identify high- sinuosity, low-gradient (e.g., Indus Fan channels) and low-sinuosity, high- gradient (e.g., Porcupine Seabight channels) channel systems as end members. Current classifications of submarine fans relate fan shape to grain size or sediment caliber and therefore are inadequate, principally because the shape of the fan is strongly controlled by the shape of the receiving basin, which in turn is dependent upon parameters such as tectonics and diapirism. Overall fan shape is almost invariably independent of the physics of sediment transport. Rather than fan shape, the geometry and other characteristics of submarine channels and canyons provide a more promising means of differentiating deep- marine turbidite systems.

  7. Human KIAA1018/FAN1 nuclease is a new mitotic substrate of APC/CCdh1

    Institute of Scientific and Technical Information of China (English)

    Fenju Lai; Kaishun Hu; Yuanzhong Wu; Jianjun Tang; Yi Sang; Jingying Cao; Tiebang Kang

    2012-01-01

    A recently identified protein,FAN1 (FANCD2-associated nuclease 1,previously known as KIAA1018),is a novel nuclease associated with monoubiquitinated FANCD2 that is required for cellular resistance against DNA interstrand crosslinking (ICL) agents.The mechanisms of FAN1 regulation have not yet been explored.Here,we provide evidence that FAN1 is degraded during mitotic exit,suggesting that FAN1 may be a mitotic substrate of the anaphase-promoting cyclosome complex (APC/C).Indeed,.Cdh1,but not Cdc20,was capable of regulating the protein level of FAN1 through the KEN box and the D-box.Moreover,the up- and down-regulation of FAN1 affected the progression to mitotic exit.Collectively,these data suggest that FAN1 may be a new mitotic substrate of APC/CCdh1 that plays a key role during mitotic e xit.

  8. Modal analysis of an aircraft engine fan noise

    Science.gov (United States)

    Gorodkova, Natalia; Chursin, Valeriy; Bersenev, Yuliy; Burdakov, Ruslan; Siner, Aleksandr; Viskova, Tatiana

    2016-10-01

    The fan is one of the main noise sources of an aircraft engine. To reduce fan noise and provide liner optimization in the inlet it is necessary to research modal structure of the fan noise. The present paper contains results of acoustic tests on installation for mode generation that consists of 34-channel generator and the inlet updated for mounting of 100 microphones, the experiments were provided in new anechoic chamber of Perm National Research Polytechnic University, the engine with the same inlet was also tested in the open test bench conditions, and results of the fan noise modal structure are presented. For modal structure educting, all 100 channels were synchronously registered in a given frequency range. The measured data were analyzed with PULSE analyzer using fast Fourier transform with a frequency resolution 8..16 Hz. Single modes with numbers from 0 to 35 at frequencies 500; 630; 800; 1000; 1250; 1600 Hz and different combinations of modes at frequencies 1000, 1600, 2000, 2500 Hz were set during tests. Modes with small enough numbers are generated well on the laboratory installation, high-number modes generate additional modes caused by a complicated interference pattern of sound field in the inlet. Open test bench results showed that there are also a lot of harmonic components at frequencies lower than fan BPF. Under 0.65 of cut off there is only one distinct mode, other modes with close and less numbers appear from 0.7 of cut off and above. At power regimes 0.76 and 0.94 of cut off the highest mode also changes from positive to negative mode number area. Numbers of the highest modes change smoothly enough with the growth of power regime. At power regimes with Mach>1 (0.7 of cut off and above) on circumference of blade wheel there is a well-defined noise of shock waves at rotor frequency harmonics that appears at the range between the first rotor frequency and fan blade passing frequency (BPF). It is planned to continue researching of sound field

  9. Analysis of Axial Flow Ventilation Fans by Vortex - Method.

    Science.gov (United States)

    Hardin, Richard Anthony

    A steady vortex-lattice method is used to solve the lifting surface equation for an axial flow fan. The type of fan studied is designed for industrial and ventilation applications and in thermofluid systems such as cooling towers. The fan blades are thin cambered surfaces manufactured from metal sheets. The numerical approach is inviscid and results in a boundary value problem with viscous effects partially accounted for by application of drag coefficient data. A non-linear wake alignment procedure is used to account for the effects of vorticity shedding in the wake and variation in wake geometry with operating conditions. The wake alignment procedure is semi-free with wake input parameters required for accurate use of the technique. A study of the wake parameters was conducted and gave trends in the variation of their values with flow rate. At "free-air" conditions, flow visualization estimates of these parameters were found to agree with those from the computations. Comparisons are made between the measured and predicted fan performance with and without a surrounding duct. The comparison of the results were especially good at the "free-air" condition using wake parameters determined from flow visualization and an inlet velocity profile measured using hot-wire anemometry. To enable better understanding of basic flow phenomena and to provide data for verification of numerical analyses, a method for measuring unsteady surface pressure on a rotating axial-flow fan blade was devised. Unsteadiness of pressure on the blade surfaces is due to the effects of upstream fan motor supports and other installation features. A pressure transducer and signal amplification circuit were mounted on a circuit board at the rotating hub with signals taken off the rotating shaft through copper disk-mercury slip rings. The pressure difference across the blade was determined and the data were corrected for time lag and distortion caused by the length of tubing. The pressure difference

  10. The Systematist's Muse – two new damselfly species from 'Elisabetha' in the Congo Basin (Odonata: Chlorocyphidae, Platycnemididae)

    NARCIS (Netherlands)

    Dijkstra, K.-D.B.

    2008-01-01

    Platycypha eliseva spec. nov. and Mesocnemis saralisa spec. nov. are described from Lokutu (formerly Elisabetha) in the Democratic Republic of Congo. The taxonomy and distribution of Platycypha and Mesocnemis are discussed and keys are provided for the males.

  11. Perceived ethical leadership in relation to employees’ organisational commitment in an organisation in the Democratic Republic of Congo

    National Research Council Canada - National Science Library

    Mitonga-Monga, Jeremy; Cilliers, Frans

    2016-01-01

    ... quantitative survey approach was used, with a non-probability purposive sample of 839 employees from a railway organisation in the Democratic Republic of the Congo. The results indicate that ethical ...

  12. The Systematist's Muse – two new damselfly species from 'Elisabetha' in the Congo Basin (Odonata: Chlorocyphidae, Platycnemididae)

    NARCIS (Netherlands)

    Dijkstra, K.-D.B.

    2008-01-01

    Platycypha eliseva spec. nov. and Mesocnemis saralisa spec. nov. are described from Lokutu (formerly Elisabetha) in the Democratic Republic of Congo. The taxonomy and distribution of Platycypha and Mesocnemis are discussed and keys are provided for the males.

  13. Young displacements on the Atacama Fault System, northern Chile from field observations and cosmogenic 21Ne concentrations

    Science.gov (United States)

    GonzáLez L., Gabriel; Dunai, Tibor; Carrizo, Daniel; Allmendinger, Richard

    2006-06-01

    We present the first numerical age constraint for young deformation of the Atacama Fault System (AFS) in northern Chile. The young activity of the AFS is expressed by several fault scarps which affects alluvial fan sediments of the eastern side of the Coastal Cordillera (23°30'-23°42'S). Detailed mapping of alluvial fans reveals a complex relationship between fault motion, erosion and alluvial fan development. An older group of alluvial fans became inactive prior to the scarp formation. Younger alluvial fans, arising directly from feeder channels and entrenched in the fault scarps, posts date the scarp formation. The youngest slip on the AFS is recorded by headward eroding channels entrenched across the scarp which are in turn displaced vertically 0.3-0.5 m by the fault. Quartz fragments in four sites on the older inactive fan group were analyzed for cosmogenic 21Ne concentrations yielding an average age of 424 ± 151 ka, the upper limit for the recent activity of the fault. Combined with the height of fault scarp, we calculate a 0.01 mm/yr minimum vertical fault slip rate. Thus young displacement on the AFS is Quaternary in age and confined to the late Pleistocene.

  14. Active Control of Fan Noise: Feasibility Study. Volume 3; Active Fan Noise Cancellation in the NASA Lewis Active Noise Control Fan Facility

    Science.gov (United States)

    Pla, Frederic G.; Hu, Ziqiang; Sutliff, Daniel L.

    1996-01-01

    This report describes the Active Noise Cancellation (ANC) System designed by General Electric and tested in the NASA Lewis Research Center's (LERC) 48 inch Active Noise Control Fan (ANCF). The goal of this study is to assess the feasibility of using wall mounted secondary acoustic sources and sensors within the duct of a high bypass turbofan aircraft engine for global active noise cancellation of fan tones. The GE ANC system is based on a modal control approach. A known acoustic mode propagating in the fan duct is canceled using an array of flush-mounted compact sound sources. The canceling modal signal is generated by a modal controller. Inputs to the controller are signals from a shaft encoder and from a microphone array which senses the residual acoustic mode in the duct. The key results are that the (6,0) was completely eliminated at the 920 Hz design frequency and substantially reduced elsewhere. The total tone power was reduced 6.8 dB (out of a possible 9.8 dB). Farfield reductions of 15 dB (SPL) were obtained. The (4,0) and (4,1) modes were reduced simultaneously yielding a 15 dB PWL decrease. The results indicate that global attenuation of PWL at the target frequency was obtained in the aft quadrant using an ANC actuator and sensor system totally contained within the duct. The quality of the results depended on precise mode generation. High spillover into spurious modes generated by the ANC actuator array caused less than optimum levels of PWL reduction. The variation in spillover is believed to be due to calibration procedure, but must be confirmed in subsequent tests.

  15. Seismic reflection survey in Omama fan area, Gunma prefecture; Gunma Omama senjochi ni okeru hanshaho jishin tansa

    Energy Technology Data Exchange (ETDEWEB)

    Yamaguchi, K.; Kano, N.; Yokokura, T.; Kiguchi, T.; Yokota, T.; Matsushima, J. [Geological Survey of Japan, Tsukuba (Japan)

    1996-10-01

    Seismic reflection survey was performed for the Medial Tectonic Line, an important geological tectonic line in the Kanto plains, at Kushibiki district, Saitama prefecture in the north-western part of the Kanto plains. It was estimated that movements of the basement were different in the individual sides of the active fault. In this study, the seismic reflection survey was performed at the Omama fan area, Gunma prefecture, which is located at the north-eastern extension of the Kushibiki plateau, to grasp the structure of basement to the depth of about 1.0 s of return travel time, and the upper sediments. Two traverse lines passing Ota city, Kiryu city, and Nitta town were used. Southern part of the traverse line-1 was in the bottom land in the middle of Tone river, and northern part was in the Omama fan area. The ground surface along the traverse line was flat. Hachioji heights are the heights elongating in the NW-SE direction and having relative height of 100 to 200 m against the surrounding plain. Another traverse line-2 was set on the steep slope having relative height more than 100 m. The Brute stack time section of each traverse line was characterized by the gradient reflection surface AA of the traverse line-1. It was suggested that the AA or intermittent parts of reflection surfaces deeper than AA may relate to the tectonic lines in the more ancient geological ages. 2 figs., 1 tab.

  16. Unsteady flowfield simulation of ducted prop-fan configurations

    Science.gov (United States)

    Janus, J. M.; Horstman, Howard Z.; Whitfield, David L.

    1992-01-01

    A technique for the simulation of unsteady flows in and around complex rotating machinery is presented. Additional domain decomposition mechanisms are introduced which extend the range of applicability of software developed for the time-accurate simulation of rotating machinery flowfields. The flow models uses the unsteady 3D Euler equations, discretized as a finite-volume method, utilizing a high-resolution approximate Riemann solver for cell interface flux definitions. Multiblock domain decomposition is used to partition the field radially, axially, as well as circumferentially into an ordered arrangement of blocks which exhibit varying degrees of similarity. A general high-order numerical scheme is applied to satisfy the geometric conservation law. Two configurations are presented - ducted single rotation prop-fan and a rotor-deswirl vane combination which form a single stage fan. Comparisons are made to other numerical solutions for these geometries and to available experimental data.

  17. Natures of Rotating Stall Cell in a Diagonal Flow Fan

    Institute of Scientific and Technical Information of China (English)

    N. SHIOMI; K. KANEKO; T. SETOGUCHI

    2005-01-01

    In order to clarify the natures of a rotating stall cell, the experimental investigation was carried out in a high specific-speed diagonal flow fan. The pressure field on the casing wall and the velocity fields at the rotor inlet and outlet were measured under rotating stall condition with a fast response pressure transducer and a single slant hot-wire probe, respectively. The data were processed using the "Double Phase-Locked Averaging (DPLA)"technique, which enabled to obtain the unsteady flow field with a rotating stall cell in the relative co-ordinate system fixed to the rotor. As a result, the structure and behavior of the rotating stall cell in a high specific-speed diagonal flow fan were shown.

  18. Pattern recognition: A dialogue on racism in fan communities [symposium

    Directory of Open Access Journals (Sweden)

    TWC Editor

    2009-11-01

    Full Text Available In early 2009, science fiction fandom's online landscape erupted with discussions of race. A post regarding cultural appropriation on author Elizabeth Bear's blog sparked a wide-ranging conversation that soon became acrimonious, with professional science fiction and fantasy writers and fans of science fiction literature and media weighing in. More recently, criticisms of Patricia C. Wrede's decision to set her young adult novel, The Thirteenth Child (2009, in an America empty of indigenous people have spearheaded new waves of discussion. Often the more widely read summaries of these debates have focused on what they mean for writers and aspiring writers who plan to represent minority cultures in their works. But what has their significance been for members of fan communities?

  19. Compressor-fan unitary structure for air conditioning system

    Science.gov (United States)

    Dreiman, N.

    2015-08-01

    An extremely compact, therefore space saving unitary structure of short axial length is produced by radial integration of a revolving piston rotary compressor and an impeller of a centrifugal fan. The unitary structure employs single motor to run as the compressor so the airflow fan and eliminates duality of motors, related power supply and control elements. Novel revolving piston rotary compressor which provides possibility for such integration comprises the following: a suction gas delivery system which provides cooling of the motor and supplies refrigerant into the suction chamber under higher pressure (supercharged); a modified discharge system and lubricating oil supply system. Axial passages formed in the stationary crankshaft are used to supply discharge gas to a condenser, to return vaporized cooling agent from the evaporator to the suction cavity of the compressor, to pass a lubricant and to accommodate wiring supplying power to the unitary structure driver -external rotor electric motor.

  20. Wake Management Strategies for Reduction of Turbomachinery Fan Noise

    Science.gov (United States)

    Waitz, Ian A.

    1998-01-01

    The primary objective of our work was to evaluate and test several wake management schemes for the reduction of turbomachinery fan noise. Throughout the course of this work we relied on several tools. These include 1) Two-dimensional steady boundary-layer and wake analyses using MISES (a thin-shear layer Navier-Stokes code), 2) Two-dimensional unsteady wake-stator interaction simulations using UNSFLO, 3) Three-dimensional, steady Navier-Stokes rotor simulations using NEWT, 4) Internal blade passage design using quasi-one-dimensional passage flow models developed at MIT, 5) Acoustic modeling using LINSUB, 6) Acoustic modeling using VO72, 7) Experiments in a low-speed cascade wind-tunnel, and 8) ADP fan rig tests in the MIT Blowdown Compressor.

  1. Experimental investigation of unsteady fan flow interaction with downstream struts

    Science.gov (United States)

    Ng, W. F.; Obrien, W. F.; Olsen, T. L.

    1986-07-01

    In the present study of the unsteady pressure field produced on fan rotor blades by interaction with downstream struts, a single stage, low speed axial-flow fan was instrumented with blade-mounted high frequency pressure transducers. In addition, stationary pressure problems were used to map out the flowfield. Fluctuating pressure measurements are presented for blade midspan and 85-percent span on both the suction and pressure surfaces of the rotor blades at several positions of the downstream struts, and for two different flow coefficients. The strut is found to produce an effect on the unsteady pressure field on the rotor blades; this effect exceeds that due to the stator at design rotor-stator-strut spacing, but it rapidly declines as the struts are moved downstream.

  2. Advanced Trailing Edge Blowing Concepts for Fan Noise Control

    Directory of Open Access Journals (Sweden)

    Cezar RIZEA

    2012-03-01

    Full Text Available This study documents trailing edge blowing research performed to reduce rotor / stator interaction noise in turbofan engines. The existing technique of filling every velocity deficit requires a large amount of air and is therefore impractical. The purpose of this research is to investigate new blowing configurations in order to achieve noise reduction with lesser amounts of air. Using the new configurations air is not injected into every fan blade, but is instead varied circumferentially. For example, blowing air may be applied to alternating fan blades. This type of blowing configuration both reduces the amount of air used and changes the spectral shape of the tonal interaction noise. The original tones at the blade passing frequency and its harmonics are reduced and new tones are introduced between them. This change in the tonal spectral shape increases the performance of acoustic liners used in conjunction with trailing edge blowing.

  3. A hospital survey of the clinical features of diabetes in Congo.

    Science.gov (United States)

    Mottini, G; D'Avola, D; Dimbelolo, J C; Lumu, R; Gallizioli, E; Nisita, J; Manfrini, S; De Clerck, M; Pozzilli, P

    2003-08-01

    The occurrence of diabetes mellitus is increasing throughout the world, both in industrialised nations and in developing countries. While this disease is not a leading cause of death in developing country populations, it must nevertheless be considered for its social and economic impact. This study examines the clinical and epidemiological situation of diabetes mellitus in the city of Kinshasa, Democratic Republic of Congo, as based on data from two city hospitals: Saint Joseph's Hospital (SJH) and the Centre Hospitalier Monkole (CHM), two urban health facilities typical of those developing countries. The results show that diabetes is a real public health problem in Congo. Average blood glucose levels were above 300 mg/dl in 44.4% of patients at SJH and 41.5% at CHM, and hypertension (> or = 140/90 mmHg) was reported in 35.8% of patients at SJH and 20% at CHM. The management of diabetes and, in particular, its complications is suffering because of some cultural influences but mainly economic ones. In fact, incidence of disease complications is closely linked to the financial status of patients and facilities. SJH, which serves mainly the low-income community, has a greater incidence of severe diabetes-associated complications than CHM, which treats patients with a higher mean income level. SJH hospitalised patients had a 24.7% incidence of diabetic foot with 3 amputations as compared to only a 10% incidence and no amputations for CHM hospitalised patients. At SJH, 17.3% of patients died during the study, while at CHM none died. Overall, differences in the prevalence of complications between SJH and CHM patients were found not to be significant. For the large majority of Congo population, education on diabetes is not available, and due to the failure of the national health system, access to treatment is impossible. Furthermore, because most diabetic people in Congo go untreated, the mortality rate for the disease is high. Congo would greatly benefit from a national

  4. Refining the Bengal Fan stratigraphy - A first correlation of IODP Expedition 354 results and seismic data from the Bay of Bengal

    Science.gov (United States)

    Schwenk, Tilmann; Spiess, Volkhard; Bergmann, Fenna; France-Lanord, Christian; Klaus, Adam

    2016-04-01

    The Bengal Fan covers the floor of the entire Bay of Bengal from the continental margins of India and Bangladesh to the sediment-filled Sunda Trench off Myanmar and the Andaman Islands, and along the west side of the Ninetyeast Ridge. The deposition and progradation of the Bengal Fan started in the Eocene after the collision of India with Asia resulting in the build-up of the Himalaya and the formation of a large proto-Bay of Bengal. Continued convergence of the Indian and Australian plates with the Southeast Asian plate reduced the size of the bay and focused the source of turbidites finally into the present Bengal Basin, Bangladesh shelf, and the shelf canyon "Swatch of no Ground". Today, the Bengal Fan is mainly fed by the sediment load of the Ganges and Brahmaputra rivers, which drain the Himalayas at its southern and northern slope, respectively, and deliver their load to the delta in the Bengal Basin, to the Bengal Shelf and to the deep sea fan. Thus the Bengal Fan is a suitable recorder to study interactions among the growth of the Himalaya and Tibet, the development of the Asian monsoon, and processes affecting the carbon cycle and global climate. Because sedimentation in the Bengal Fan responds to both, climate and tectonic processes, its terrigenous sediment records the past evolution of both the Himalaya and regional climate. This evolution is also expressed in the stratigraphy of the fan in terms of unconformities and key horizons, average sedimentation rates as a function of distance from the basement ridges at 85°E and 90°E and the presence or absence of channel-levee systems. The histories of the Himalaya/Tibetan system and the Asian monsoon require sampling different periods of time with different levels of precision. Therefore IODP Expedition 354 drilled in February-March 2015 a seven site, 320 km-long transect across the Bengal Fan at 8°N. This strategy has been chosen because sediment transport took place by turbidity currents following

  5. Determination of serum adenosine deaminase and xanthine oxidase levels in patients with crimean-congo hemorrhagic fever

    Directory of Open Access Journals (Sweden)

    V. Kenan Celik

    2010-01-01

    Full Text Available OBJECTIVE: Crimean-Congo hemorrhagic fever is an acute viral hemorrhagic fever with a high mortality rate. Despite increasing knowledge about hemorrhagic fever viruses, little is known about the pathogenesis of Crimean-Congo hemorrhagic fever. In this study, we measured serum adenosine deaminase and xanthine oxidase levels in Crimean-Congo hemorrhagic fever patients. METHODS: Serum adenosine deaminase levels were measured with a sensitive colorimetric method described by Giusti and xanthine oxidase levels by the method of Worthington in 30 consecutive hospitalized patients (mean age 42.6 ± 21.0. Laboratory tests confirmed their diagnoses of Crimean-Congo hemorrhagic fever. Thirty-five subjects (mean age 42.9 ± 19.1 served as the control group. RESULTS: There was a significant difference in adenosine deaminase and xanthine oxidase levels between cases and controls (p0.05. CONCLUSION: Adenosine deaminase and xanthine oxidase levels were increased in patients with Crimean-Congo hemorrhagic fever. Elevated serum xanthine oxidase activity in patients with Crimean-Congo hemorrhagic fever may be associated with reactive oxygen species generated by the xanthine/xanthine oxidase system during inflammatory responses. In addition, elevated lipid peroxidation may contribute to cell damage and hemorrhage. The association of cell damage and hemorrhage with xanthine oxidase activity should be further investigated in large-scale studies.

  6. Euler/Navier-Stokes Solvers Applied to Ducted Fan Configurations

    Science.gov (United States)

    Keith, Theo G., Jr.; Srivastava, Rakesh

    1997-01-01

    Due to noise considerations, ultra high bypass ducted fans have become a more viable design. These ducted fans typically consist of a rotor stage containing a wide chord fan and a stator stage. One of the concerns for this design is the classical flutter that keeps occurring in various unducted fan blade designs. These flutter are catastrophic and are to be avoided in the flight envelope of the engine. Some numerical investigations by Williams, Cho and Dalton, have suggested that a duct around a propeller makes it more unstable. This needs to be further investigated. In order to design an engine to safely perform a set of desired tasks, accurate information of the stresses on the blade during the entire cycle of blade motion is required. This requirement in turn demands that accurate knowledge of steady and unsteady blade loading be available. Aerodynamic solvers based on unsteady three-dimensional analysis will provide accurate and fast solutions and are best suited for aeroelastic analysis. The Euler solvers capture significant physics of the flowfield and are reasonably fast. An aerodynamic solver Ref. based on Euler equations had been developed under a separate grant from NASA Lewis in the past. Under the current grant, this solver has been modified to calculate the aeroelastic characteristics of unducted and ducted rotors. Even though, the aeroelastic solver based on three-dimensional Euler equations is computationally efficient, it is still very expensive to investigate the effects of multiple stages on the aeroelastic characteristics. In order to investigate the effects of multiple stages, a two-dimensional multi stage aeroelastic solver was also developed under this task, in collaboration with Dr. T. S. R. Reddy of the University of Toledo. Both of these solvers were applied to several test cases and validated against experimental data, where available.

  7. Instrumentation for propulsion systems development. [high speed fans and turbines

    Science.gov (United States)

    Warshawsky, I.

    1978-01-01

    Apparatus and techniques developed or used by NASA-Lewis to make steady state or dynamic measurements of gas temperature, pressure, and velocity and of the temperature, tip clearance, and vibration of the blades of high-speed fans or turbines are described. The advantages and limitations of each instrument and technique are discussed and the possibility of modifying them for use in developing various propulsion systems is suggested.

  8. GENERALIZATIONS OF KY FAN'S THEOREM ON BEST APPROXIMATIONS

    Institute of Scientific and Technical Information of China (English)

    T.D.Narang

    2009-01-01

    In 1969, Ky Fan[3] proved that for any continuous function f from a compact convex subset M of a normed linear space X into X, there exists x ∈ M such that ||f(x)-x|| = dist(f(x),M). Since then, there have appeared several generalizations, extensions and applications of this result. This paper also deals with some extensions and generalizations of this result when the underlying spaces are convex metric spaces.

  9. The Diagonal Compression Field Method using Circular Fans

    DEFF Research Database (Denmark)

    Hansen, Thomas

    2005-01-01

    This paper presents a new design method, which is a modification of the diagonal compression field method, the modification consisting of the introduction of circular fan stress fields. The traditional method does not allow changes of the concrete compression direction throughout a given beam...... fields may be used whenever changes in the concrete compression direction are desired. To illustrate the new design method, a specific example of a prestressed concrete beam is calculated....

  10. Fans of Columbine shooters Eric Harris and Dylan Klebold

    OpenAIRE

    Andrew Ryan Rico

    2015-01-01

    On April 20, 1999, Eric Harris and Dylan Klebold murdered 12 students and one teacher at Columbine High School in Littleton, Colorado, in what was then the deadliest school shooting in American history. Despite causing a national panic and serving as a flash point for larger narratives on bullying, gun control, and media violence, both boys have gained active online fans. These fandoms dedicated to the Columbine shooters are widely referred to as dark examples of Internet communities, while t...

  11. Aerodynamic optimisation of an industrial axial fan blade

    OpenAIRE

    2006-01-01

    Numerical optimisation methods have successfully been used for a variety of aerodynamic design problems over quite a few years. However the application of these methods to the aerodynamic blade shape optimisation of industrial axial fans has received much less attention in the literature probably given the fact that the majority of resources available to develop these automated design approaches is to be found in the aerospace field. This work presents the develo...

  12. Dual Fan Separator within the Universal Waste Management System

    Science.gov (United States)

    Stapleton, Tom; Converse, Dave; Broyan, James Lee, Jr.

    2014-01-01

    Since NASA's new spacecraft in development for both LEO and Deep Space capability have considerable crew volume reduction in comparison to the Space Shuttle, the need became apparent for a smaller commode. In response the Universal Waste Management System (UWMS) was designed, resulting in an 80% volume reduction from the last US commode, while enhancing performance. The ISS WMS and previous shuttle commodes have a fan supplying air flow to capture feces and a separator to capture urine and separate air from the captured air/urine mixture. The UWMS combined both rotating equipment components into a single unit, referred to at the Dual Fan Separator (DFS). The combination of these components resulted in considerable packaging efficiency and weight reduction, removing inter-component plumbing, individual mounting configurations and required only a single motor and motor controller, in some of the intended UWMS platform applications the urine is pumped to the ISS Urine Processor Assembly (UPA) system. It requires the DFS to include less than 2.00% air inclusion, by volume, in the delivered urine. The rotational speed needs to be kept as low as possible in centrifugal urine separators to reduce air inclusion in the pumped fluid, while fans depend on rotational speed to develop delivered head. To satisfy these conflicting requirements, a gear reducer was included, allowing the fans to rotate at a much higher speed than the separator. This paper outlines the studies and analysis performed to develop the DFS configuration. The studies included a configuration trade study, dynamic stability analysis of the rotating bodies and a performance analysis of included labyrinth seals. NASA is considering a program to fly the UWMS aboard the ISS as a flight experiment. The goal of this activity is to advance the Technical Readiness Level (TRL) of the DFS and determine if the concept is ready to be included as part of the flight experiment deliverable.

  13. Stable fan filter design using two-variable reactance functions

    Science.gov (United States)

    Bruton, L. T.; Bartley, N. R.

    1982-03-01

    Two-variable reactance transformation (as proposed by King et al., 1982) for the design of stable two-dimensional recursive fan filters with narrow stopbands is compared with the design method proposed by Bruton et al. (1981) using numerical optimization of a resistively terminated (2 + n sub 1 + n sub 2)-port network. The method of King et al. is found to be definitely more simple to design.

  14. iFan iphone风力充电器

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    你还在每天为了寻找为iPhone充电的电源而烦恼么?这里有一款非常给力的iPhone手机配件——iFan iPhone风力充电器。在充当保护套之外它头顶上的风扇可以收集风能转化为电能给iPhone充电。

  15. Evaluation of Retrofit Variable-Speed Furnace Fan Motors

    Energy Technology Data Exchange (ETDEWEB)

    Aldrich, R.; Williamson, J.

    2014-01-01

    In conjunction with the New York State Energy Research and Development Authority (NYSERDA) and Proctor Engineering Group, Ltd. (PEG), the Consortium for Advanced Residential Buildings (CARB) has evaluated the Concept 3 (tm) replacement motors for residential furnaces. These brushless, permanent magnet (BPM) motors can use much less electricity than their PSC (permanent split capacitor) predecessors. This evaluation focuses on existing homes in the heating-dominated climate of upstate New York with the goals of characterizing field performance and cost-effectiveness. The results of this study are intended to be useful to home performance contractors, HVAC contractors, and home efficiency program stakeholders. The project includes eight homes in and near Syracuse, NY. Tests and monitoring was performed both before and after fan motors were replaced. Average fan power reductions were approximately 126 Watts during heating and 220 Watts during cooling operation. Over the course of entire heating and cooling seasons, these translated into average electric energy savings of 163 kWh. Average cost savings were $20 per year. Homes where the fan was used outside of heating and cooling mode saved an additional $42 per year on average. Results indicate that BPM replacement motors will be most cost-effective in HVAC systems with longer run times and relatively low duct static pressures. More dramatic savings are possible if occupants use the fan-only setting when there is no thermal load. There are millions of cold-climate, U.S. homes that meet these criteria, but the savings in most homes tested in this study were modest.

  16. Streaming Scholarship: Using Fan Vids to Teach "Harry Potter"

    Science.gov (United States)

    Winters, Sarah Fiona

    2013-01-01

    This article argues that Harry Potter fan vids can be used in the classroom as works of secondary criticism about J. K. Rowling's primary text. It makes two claims: the first is that vids can be read as criticism of a particular text (in this case Harry Potter) alongside other critical essays on that text; the second is that the practice of…

  17. Streaming Scholarship: Using Fan Vids to Teach "Harry Potter"

    Science.gov (United States)

    Winters, Sarah Fiona

    2013-01-01

    This article argues that Harry Potter fan vids can be used in the classroom as works of secondary criticism about J. K. Rowling's primary text. It makes two claims: the first is that vids can be read as criticism of a particular text (in this case Harry Potter) alongside other critical essays on that text; the second is that the practice of…

  18. Fan Atomized Burner design advances & commercial development progress

    Energy Technology Data Exchange (ETDEWEB)

    Kamath, B. [Heat-Wise, Inc., Ridge, NY (United States); Butcher, T.A. [Brookhaven National Lab., Upton, NY (United States)

    1996-07-01

    As a part of the Oil Heat Research and Development program, sponsored by the US Department of Energy, Brookhaven National Laboratory (BNL) has an on-going interest in advanced combustion technologies. This interest is aimed at: improving the initial efficiency of heating equipment, reducing long term fouling and efficiency degradation, reducing air pollutant emissions, and providing practical low-firing rate technologies which may lead to new, high efficiency oil-fired appliances. The Fan-Atomized Burner (FAB) technology is being developed at BNL as part of this general goal. The Fan-Atomized Burner uses a low pressure, air atomizing nozzle in place of the high pressure nozzle used in conventional burners. Because it is air-atomized the burner can operate at low firing rates without the small passages and reliability concerns of low input pressure nozzles. Because it uses a low pressure nozzle the burner can use a fan in place of the small compressor used in other air-atomized burner designs. High initial efficiency of heating equipment is achieved because the burner can operate at very low excess air levels. These low excess air levels also reduce the formation of sulfuric acid in flames. Sulfuric acid is responsible for scaling and fouling of heat exchanger surfaces.

  19. Auxiliary lift propulsion system with oversized front fan

    Energy Technology Data Exchange (ETDEWEB)

    Castells, O.T.; Johnson, J.E.; Rundell, D.J.

    1980-09-16

    A propulsion system for use primarily in V/STOL aircraft is provided with a variable cycle, double bypass gas turbofan engine and a remote augmenter to produce auxiliary lift. The fan is oversized in air-pumping capability with respect to the cruise flight requirements of the remainder of the engine and a variable area, low pressure turbine is capable of supplying varying amounts of rotational energy to the oversized fan, thereby modulating its speed and pumping capability. During powered lift flight, the variable cycle engine is operated in the single bypass mode with the oversized fan at its maximum pumping capability. In this mode, substantially all of the bypass flow is routed as an auxiliary airstream to the remote augmenter where it is mixed with fuel, burned and exhausted through a vectorable nozzle to produce thrust for lifting. Additional lift is generated by the high energy products of combustion of the variable cycle engine which are further energized in an afterburner and exhausted through a thrust vectorable nozzle at the rear of the engine.

  20. Characteristics of tip-leakage flow in an axial fan

    Science.gov (United States)

    Park, Keuntae; Choi, Haecheon; Choi, Seokho; Sa, Yongcheol

    2014-11-01

    An axial fan with a shroud generates complicated vortical structures by the interaction of the axial flow with the fan blades and shroud near the blade tips. Large eddy simulation (LES) is performed for flow through a forward-swept axial fan, operating at the design condition of Re = 547,000 based on the radius of blade tip and the tip velocity. A dynamic global model (Lee et al. 2010) is used for a subgrid-scale model, and an immersed boundary method in a non-inertial reference frame (Kim & Choi 2006) is adopted for the present simulation. It is found that two vortical structures are formed near the blade tip: the main tip leakage vortex (TLV) and the auxiliary TLV. The main TLV is initiated near the leading edge, develops downstream, and impinges on the pressure surface of the next blade, where the pressure fluctuations and turbulence intensity become high. On the other hand, the auxiliary TLV is initiated at the aft part of the blade but is relatively weak such that it merges with the main TLV. Supported by the KISTI Supercomputing Center (KSC-2014-C2-014).

  1. Investigation of fatigue fracture of generator-rotor fan blades

    Energy Technology Data Exchange (ETDEWEB)

    Sameezadeh, Mahmood; Farhangi, Hassan [School of Metallurgy and Materials Engineering, Univ. of Tehran (Iran); Soltani, Nasser [School of Mechanical Engineering, Univ. of Tehran (Iran); Ataei, Peyman [Dept. of Metallurgy and Materials Engineering, South Tehran Branch of Azad Univ., Tehran (Iran)

    2009-11-15

    The failure of a rotating axial flow fan of a 123 MW electric power generator unit is analyzed. The fan was mounted on the generator-rotor at the turbine end. Initial investigations showed that three fan blades had fractured just about 11 h after resuming operation following the last overhaul, causing extensive damage to the unit. The failure of the blades was investigated using fractographic and microstructural characterization techniques as well as mechanical evaluations. Based on fractographic observations high cycle fatigue was identified as the failure mechanism. Formation of multiple primary cracks which coalesced during crack growth to form shallow and semi-elliptical crack geometry was indicative of the influence of additional bending stresses, probably resulting from excessive vibrations. Using fracture mechanics principles, the magnitude of the maximum stress at the time of final fracture of the first broken blade was estimated to be more than 3 times higher than the design operating stress. Furthermore, crack growth lifetime of the blades was evaluated using FRANC3D software. It was found that an operating period of just about one hour was required for small initial cracks to propagate to final failure under the action of excessive bending stresses. (orig.)

  2. Effects of Bifurcations on Aft-Fan Engine Nacelle Noise

    Science.gov (United States)

    Nark, Douglas M.; Farassat, Fereidoun; Pope, D. Stuart; Vatsa, Veer N.

    2004-01-01

    Aft-fan engine nacelle noise is a significant factor in the increasingly important issue of aircraft community noise. The ability to predict such noise within complex duct geometries is a valuable tool in studying possible noise attenuation methods. A recent example of code development for such predictions is the ducted fan noise propagation and radiation code CDUCT-LaRC. This work focuses on predicting the effects of geometry changes (i.e. bifurcations, pylons) on aft fan noise propagation. Beginning with simplified geometries, calculations show that bifurcations lead to scattering of acoustic energy into higher order modes. In addition, when circumferential mode number and the number of bifurcations are properly commensurate, bifurcations increase the relative importance of the plane wave mode near the exhaust plane of the bypass duct. This is particularly evident when the bypass duct surfaces include acoustic treatment. Calculations involving more complex geometries further illustrate that bifurcations and pylons clearly affect modal content, in both propagation and radiation calculations. Additionally, results show that consideration of acoustic radiation results may provide further insight into acoustic treatment effectiveness for situations in which modal decomposition may not be straightforward. The ability of CDUCT-LaRC to handle complex (non-axisymmetric) multi-block geometries, as well as axially and circumferentially segmented liners, allows investigation into the effects of geometric elements (bifurcations, pylons).

  3. Multivariate real-time assessment of droughts via copula-based multi-site Hazard Trajectories and Fans

    Science.gov (United States)

    Salvadori, G.; De Michele, C.

    2015-07-01

    Droughts, like floods, represent the most dangerous, and costly, water cycle expressions, with huge impacts on society and built environment. Droughts are events occurring over a certain region, lasting several weeks or months, and involving multiple variables: thus, a multivariate, multi-site, approach is most appropriate for their statistical characterization. In this methodological work, hydrological droughts are considered, and a multivariate approach is proposed, by regarding as relevant variables the duration and the average intensity. A multivariate, multi-site, frequency analysis is presented, based on the Theory of Copulas and the joint Survival Kendall's Return Periods, by investigating the historical drought episodes occurred at five main river sections of the Po river (Northern Italy), the most important Italian basin. The tool of Dynamic Return Period is used, and the new concepts of Hazard Trajectories and Fans are introduced, in order to provide useful indications for a valuable multi-site real-time assessment of droughts.

  4. River terraces and alluvial fans: The case for an integrated Quaternary fluvial archive

    Science.gov (United States)

    Mather, A. E.; Stokes, M.; Whitfield, E.

    2017-06-01

    The fluvial archive literature is dominated by research on river terraces with appropriate mention of adjacent environments such as lakes. Despite modern sedimentary basins comprising a significant (>88%) volume of distributive fluvial systems, of which alluvial fans (>1 km, archive community. Published literature is used to examine both thematic and geographical based benefits of alluvial fan research that can assist understanding of Quaternary fluvial archives. 3 regional case studies are presented that illustrate the interaction between alluvial fan and river terrace archives at Quaternary time-scales at 3 different stages of landscape evolution. These are i) continuous mountain front alluvial fans interacting with a non incising but laterally eroding axial fluvial system; ii) alluvial fans which transition into fluvial terraces as sedimentary basins shift from net aggradation to net incision and iii) tributary-junction alluvial fans that develop predominantly within incising river valley systems. A simple conceptual model is proposed to summarise the dynamic role of alluvial fans within this landscape context. The alluvial fans act as potential 'buffers' between hillslopes and river terrace records under 'top down' climate-driven high sediment supply and alluvial fan aggradation, and 'couplers' during periods of less sediment (in relation to water) discharge and alluvial fan incision. These dynamics will change with the addition of 'bottom up' controls such as main river incision, which will typically enhance the coupling effect of both systems.

  5. The Conceptual Design of High Pressure Reversible Axial Tunnel Ventilation Fans

    Directory of Open Access Journals (Sweden)

    A. G. Sheard

    2012-01-01

    Full Text Available Tunnel ventilation fans, classically, must have the ability to both supply and extract air from a tunnel system, with the operator's choice dependent on the tunnel ventilation system's operating mode most appropriate at any given point in time. Consequently, tunnel ventilation fans must incorporate a reversible aerodynamic design which limits the maximum fan pressure rise. This paper presents three high pressure reversible fan concepts. These comprise a two-stage counter rotating fan, a single-stage high speed fan, and a two-stage fan with a single motor and impeller on each end of the motor shaft. The authors consider the relative merits of each concept. The third concept offers the most compact fan, transform, silencer, and damper package size. The authors discuss the mechanical design challenges that occur with a two-stage fan with a single motor and impeller on each end of the motor shaft. They present and consider a selected motor bearing arrangement and casing design for maintainability. Finally, the authors present both prototype fan and full-scale package aerodynamic and acoustic performance, before discussing the challenges presented by high temperature certification in accordance with the requirements of EN 12101-3: 2012.

  6. Numerical investigation of geometric parameter effects on the aerodynamic performance of a Bladeless fan

    Directory of Open Access Journals (Sweden)

    Mohammad Jafari

    2016-03-01

    Full Text Available Aerodynamic performance of a Bladeless fan is numerically investigated considering the effect of five geometric parameters. Airflow through this fan was analyzed by simulating a Bladeless fan within a 2 m × 2 m × 4 m room. Analysis of the flow field inside the fan and the evaluation of its performance were obtained by solving conservations of mass and momentum equations for the aerodynamic investigations. In order to design the Bladeless fan an Eppler 473 airfoil profile was used as the cross section of the fan. Five distinct parameters, namely height of cross section of the fan, outlet angle of the flow relative to the fan axis, thickness of airflow outlet slit, hydraulic diameter, and aspect ratio for circular and quadratic cross sections were considered. Validating 3-D numerical results, experimental results of a round jet showed good agreement with those of the simulation data. The multiplier factor M is defined to show the ratio of the outlet flow rate to inlet flow rate from the fan. The obtained numerical results showed that the Discharge ratio has the maximum value for the height of 3 cm. The numerical outcomes of outlet thickness variation indicate that this parameter is one of the most influential parameters on the aerodynamic performance of a Bladeless fan. The results for the outlet thicknesses of 1, 2 and 3 mm showed that the Discharge ratio increased significantly when the outlet thickness decreased.

  7. Experimental and Numerical Investigation of a 60cm Diameter Bladeless Fan

    Directory of Open Access Journals (Sweden)

    mohammad jafari

    2016-01-01

    Full Text Available Bladeless fan is a novel type of fan with an unusual geometry and unique characteristics. This type of fan has been recently developed for domestic applications in sizes typically up to 30cm diameter. In the present study, a Bladeless fan with a diameter of 60cm was designed and constructed, in order to investigate feasibility of its usage in various industries with large dimensions. Firstly, flow field passed through this fan was studied by 3D modeling. Aerodynamic and aeroacoustic performance of the fan were considered via solving the conservation of mass and momentum equations in their unsteady form. To validate the acoustic code, NACA 0012 airfoil was simulated in a two dimension domain and the emitted noise was calculated for Re=2×105. Good agreement between numerical and experimental results was observed by applying FW-H equations for predicting noise of the fan. To validate the simulated aerodynamic results, a Bladeless fan with a 60cm diameter was constructed and experimentally tested. In addition, the difference between the experimental and numerical results was acceptable for this fan. Moreover, the experimental results in the present study showed that this fan is capable to be designed and used for various industrial applications.

  8. Health assessment of cooling fan bearings using wavelet-based filtering.

    Science.gov (United States)

    Miao, Qiang; Tang, Chao; Liang, Wei; Pecht, Michael

    2012-12-24

    As commonly used forced convection air cooling devices in electronics, cooling fans are crucial for guaranteeing the reliability of electronic systems. In a cooling fan assembly, fan bearing failure is a major failure mode that causes excessive vibration, noise, reduction in rotation speed, locked rotor, failure to start, and other problems; therefore, it is necessary to conduct research on the health assessment of cooling fan bearings. This paper presents a vibration-based fan bearing health evaluation method using comblet filtering and exponentially weighted moving average. A new health condition indicator (HCI) for fan bearing degradation assessment is proposed. In order to collect the vibration data for validation of the proposed method, a cooling fan accelerated life test was conducted to simulate the lubricant starvation of fan bearings. A comparison between the proposed method and methods in previous studies (i.e., root mean square, kurtosis, and fault growth parameter) was carried out to assess the performance of the HCI. The analysis results suggest that the HCI can identify incipient fan bearing failures and describe the bearing degradation process. Overall, the work presented in this paper provides a promising method for fan bearing health evaluation and prognosis.

  9. Health Assessment of Cooling Fan Bearings Using Wavelet-Based Filtering

    Directory of Open Access Journals (Sweden)

    Qiang Miao

    2012-12-01

    Full Text Available As commonly used forced convection air cooling devices in electronics, cooling fans are crucial for guaranteeing the reliability of electronic systems. In a cooling fan assembly, fan bearing failure is a major failure mode that causes excessive vibration, noise, reduction in rotation speed, locked rotor, failure to start, and other problems; therefore, it is necessary to conduct research on the health assessment of cooling fan bearings. This paper presents a vibration-based fan bearing health evaluation method using comblet filtering and exponentially weighted moving average. A new health condition indicator (HCI for fan bearing degradation assessment is proposed. In order to collect the vibration data for validation of the proposed method, a cooling fan accelerated life test was conducted to simulate the lubricant starvation of fan bearings. A comparison between the proposed method and methods in previous studies (i.e., root mean square, kurtosis, and fault growth parameter was carried out to assess the performance of the HCI. The analysis results suggest that the HCI can identify incipient fan bearing failures and describe the bearing degradation process. Overall, the work presented in this paper provides a promising method for fan bearing health evaluation and prognosis.

  10. Large scale application of vibration sensors for fan monitoring at commercial layer hen houses.

    Science.gov (United States)

    Chen, Yan; Ni, Ji-Qin; Diehl, Claude A; Heber, Albert J; Bogan, Bill W; Chai, Li-Long

    2010-01-01

    Continuously monitoring the operation of each individual fan can significantly improve the measurement quality of aerial pollutant emissions from animal buildings that have a large number of fans. To monitor the fan operation by detecting the fan vibration is a relatively new technique. A low-cost electronic vibration sensor was developed and commercialized. However, its large scale application has not yet been evaluated. This paper presents long-term performance results of this vibration sensor at two large commercial layer houses. Vibration sensors were installed on 164 fans of 130 cm diameter to continuously monitor the fan on/off status for two years. The performance of the vibration sensors was compared with fan rotational speed (FRS) sensors. The vibration sensors exhibited quick response and high sensitivity to fan operations and therefore satisfied the general requirements of air quality research. The study proved that detecting fan vibration was an effective method to monitor the on/off status of a large number of single-speed fans. The vibration sensor itself was $2 more expensive than a magnetic proximity FRS sensor but the overall cost including installation and data acquisition hardware was $77 less expensive than the FRS sensor. A total of nine vibration sensors failed during the study and the failure rate was related to the batches of product. A few sensors also exhibited unsteady sensitivity. As a new product, the quality of the sensor should be improved to make it more reliable and acceptable.

  11. Study on the performance improvement of multiblade fans. Effects of suction cones; Tayoku fan no seino kaizen ni kansuru kenkyu. Suction cone no eikyo

    Energy Technology Data Exchange (ETDEWEB)

    Kuratani, F.; Ogawa, T. [Hyogo University of Teacher Education, Hyogo (Japan); Yamamoto, S.

    1999-07-25

    In order to improve the performance of a multiblade fan, the effects of three types of suction cones of the fan casing on the fan efficiency and noise are investigated experimentally. The first type of the suction cone is the insertion type, which is inserted into the inside of the fan impeller. The second type is the extrusion type, which extrudes outside from the casing surface. The third type is the combination type of two types. The results of those three types are compared with those of the commonly used suction cone. The followings are made clear: (1) The insertion type and the extrusion type are effective in improving the efficiency and reducing noise. (2) The optimal lengths of the insertion and the extrusion exist. (3) The combination type is more effective in improving the efficiency. (4) The combination type with the skewed cutoff of the fan casing shows the best effect. (author)

  12. Persistence of high fertility in tropical Africa: the case of the Democratic Republic of the Congo.

    Science.gov (United States)

    Romaniuk, Anatole

    2011-01-01

    The article explores how geography, history, and society have shaped childbearing behaviors over the last half-century, and how they are now being reshaped by modernity and the exigencies of urban life, in the democratic Republic of the Congo. The decline of prolonged postpartum abstinence and involuntary childlessness initially raised fertility to high levels (6–7 children per woman). More recently, socioeconomic differentials in fertility have emerged, suggesting that the country may be entering a phase of fertility decline. A full-blown transition, however, seems still a remote prospect. Supported both by cultural traditions and by economic rationality, Congo's people remain largely convinced of the benefits of many children for their own and their kin's security. While an eventual fertility transition may be taken for granted, the article examines the many hurdles, contradictions, and tensions that will have to be overcome to achieve that outcome.

  13. Phytochemical analysis and biological evaluation of selected African propolis samples from Cameroon and Congo.

    Science.gov (United States)

    Papachroni, Danai; Graikou, Konstantia; Kosalec, Ivan; Damianakos, Harilaos; Ingram, Verina; Chinou, Ioanna

    2015-01-01

    The objective of this study was the chemical analysis of four selected samples of African propolis (Congo and Cameroon) and their biological evaluation. Twenty-one secondary metabolites belonging to four different chemical groups were isolated from the 70% ethanolic extracts of propolis and their structures were elucidated on the basis of spectral evidence. Three triterpenes and two diprenyl-flavonoids were identified from Congo propolis, which has been investigated for the first time, while thirteen triterpenes, three diprenyl-flavonoids, two monoterpenic alcohols and one fatty acid ester have been identified from Cameroon propolis samples. To our knowledge, the identified diprenyl-flavonoids, as well as five of the isolated and determined triterpenes, are reported for the first time in propolis. Moreover, the total polyphenol content was estimated in all extracts and the antimicrobial activities of all four extracts were studied against six Gram-positive and -negative bacteria and three pathogenic fungi, showing an interesting antibacterial profile.

  14. Estado Livre do Congo: imperialismo, a roedura geopolítica (1885-1908)

    OpenAIRE

    Martinho Camargo Milani

    2011-01-01

    O presente trabalho tem por finalidade relatar a importância da Sociedade Geográfica Real Belga na exploração imperialista efetuada pela Bélgica na região do Congo africano entre 1885 e 1908. Em verdade, o Congo era uma colônia privada do rei da Bélgica, Leopoldo II. Durante o século XIX foram fundadas diversas Sociedades Geográficas pelo mundo, entre elas a Belga que apareceu em 1876, no período de institucionalização da ciência geográfica. Entender a História Africana no final do século XIX...

  15. Semantiche del terrore, della morte e della speranza nell’Est del Congo (Ituri, Kivu

    Directory of Open Access Journals (Sweden)

    Roberto Beneduce

    2013-07-01

    Full Text Available Due definizioni di immaginario saranno tenute presenti in queste pagine, rivolte ad analizzare il senso della violenza nella Repubblica Democratica del Congo (d’ora innanzi RDC o semplicemente Congo: l’una risalente a Castoriadis (1975, p. 245, per il quale l’immaginario contiene il razionale secondo una relazione indistinta e fondamentale, anzi ne è funzione e forma; l’altra a Deleuze. La prima è qui ripresa soprattutto nella formulazione offertane da Mbembe (2000, p. 203: “un insieme di segni interrelati che si presentano, in qualunque circostanza, come significato indiscutibile e indiscusso”. La seconda riconosce il carattere per eccellenza dell’immaginario nell’impossibilità di discernere, al suo interno, fra reale e irreale (Deleuze 1990, p. 92.

  16. Cutting the Flesh: Surgery, Autopsy and Cannibalism in the Belgian Congo.

    Science.gov (United States)

    Au, Sokhieng

    2017-04-01

    Within the colonial setting of the Belgian Congo, the process of cutting the body, whether living or dead, lent itself to conflation with cannibalism and other fantastic consumption stories by both Congolese and Belgian observers. In part this was due to the instability of the meaning of the human body and the human corpse in the colonial setting. This essay maps out different views of the cadaver and personhood through medical technologies of opening the body in the Belgian Congo. The attempt to impose a specific reading of the human body on the Congolese populations through anatomy and related Western medical disciplines was unsuccessful. Ultimately, practices such as surgery and autopsy were reinterpreted and reshaped in the colonial context, as were the definitions of social and medical death. By examining the conflicts that arose around medical technologies of cutting human flesh, this essay traces multiple parallel narratives on acceptable use and representation of the human body (Congolese or Belgian) beyond its medical assignation.

  17. Characterisation of a Giant Lemon Grass Acclimatised in the Congo-Brazzaville

    Directory of Open Access Journals (Sweden)

    Loumouamou Aubin Nestor

    2010-11-01

    Full Text Available The aim of this study to investigate the essential oil of the giant variety of lemon grass (Poaceae obtained from farmers in Congo-Kinshasa and tested in Congo-Brazzaville. Chemical analysis, by GC and GCMS, of the essential oil from different parts of the plant, extracted at different stages of growth, revealed the very high stability of the citral chemotype (>80%; giving it the status of interesting species for the production of citral oil. However, it could not be identified to any of the oil-yielding grasses already described in the literature. Like Cymbopogon citratus (DC Stapf it produces an essential oil containing more than 80% citral, but displays morphological characteristics of vigorous grasses. The botanical description of the plant and the chemical composition of its oil identify it to Cymbopogon densiflorus (Steud Stapf.

  18. High prevalence of syphilis among demobilized child soldiers in Eastern Congo: a cross-sectional study

    Directory of Open Access Journals (Sweden)

    Lutala Prosper

    2011-09-01

    Full Text Available Abstract Background Syphilis, a known major public health issue for soldiers during periods of conflict, is exacerbated in the Democratic Republic of Congo due to widespread sexual violence. However, there has been no previous study to determine the extent of this problem. Therefore, we determined the prevalence of syphilis among young demobilized soldiers. Methods Screening of syphilis using the rapid plasma reagin test and the Treponema pallidum hemagglutination assay was conducted in three transit sites of soldier reintegration in 2005. The Fisher Exact probability test was used to compare results. Results The prevalence of syphilis was found to be 3.4%, with almost equal distribution in respect to sex, location. Conclusion Syphilis continues to be highly prevalent in demobilized child soldiers in Eastern Congo. Syphilis screening tests are recommended.

  19. Prevalence of Crimean-Congo hemorrhagic fever in Pakistan and its new research progress

    Institute of Scientific and Technical Information of China (English)

    Maria Saleem; Syed Zawar Shah; Asma Haidari; Fatima Idrees

    2016-01-01

    Crimean-Congo hemorrhagic fever is a deadly and life-threatening viral sickness spreading throughout the world with high mortality rate of 10%–40%. The causative agents are ticks which show diversity in their strains and thus it is difficult to make vaccine, however some strains are conserved which is the positive point in vaccines development. From 2012 to 2015, a total of 161 cases were confirmed for Crimean-Congo hemorrhagic fever virus in Pakistan. And from 2012 to July 2014, 45 deaths were reported in the country. It is spreading sporadically in Pakistan. Mapping of endemic areas and cross-border veterinary surveillance should be developed in high risk areas and workshops should be arranged to increase public awareness about the disease. Control measures must be taken to avoid spreading of the disease to new areas.

  20. Transnational childrearing and the preservation of transnational identity in Brazzaville, Congo

    Science.gov (United States)

    Whitehouse, Bruce

    2013-01-01

    Drawing on ethnographic research conducted at two ends of an intra- Africa migration flow (Mali and the Republic of Congo), in this article I examine the role of childrearing practices in the maintenance of transnationalism. I consider different approaches to transnational childrearing by migrant parents and their reasons for adopting them, and delineate three common modes. The most widespread and socially validated approach is to send children home from Congo to their parents’ places of origin, where child fostering is widespread, to be raised by relatives for long periods; this approach increases the durability of transnational ties. I use childrearing approaches as an analytical lens to demonstrate the complementarity of multiple forms of domestic organization, mobility and settlement in the intergenerational production and transmission of durable transnational identities. By arguing for greater focus on phenomena such as transnational childrearing, I seek to promote a broader conceptualization of transnationalism. PMID:23935404

  1. Evaluation of Aluminium Dross as Adsorbent for Removal of Carcinogenic Congo Red Dye in Wastewater

    Science.gov (United States)

    Zakaria, Mohamad Zulfika Hazielim b.; Zauzi, Nur Syuhada Ahmad; Baini, Rubiyah; Sutan, Norsuzailina Mohamed; Rezaur Rahman, Md

    2017-06-01

    In this study, aluminium dross waste generated from aluminium smelting industries was employed as adsorbent in removing of congo red dye in aqueous solution. The raw aluminium dross as adsorbent was characterized using Scanning Electron Microscope (SEM), Brunauer-Emmett-Teller (BET) for surface area and X-Ray Fluorescence (XRF) Spectroscopy. Adsorption experiments were carried out by batch system at different adsorbent mass, pH, and initial dye concentration. The results showed that the per cent removal of dye increased as adsorbent mass increased. It was found that 0.4 gram of adsorbent can remove approximately 100 % of dye at pH 9 for dye concentration 20 and 40 ppm. Therefore, it can be concluded that raw aluminium dross without undergone any treatment can be effectively used for the adsorption of congo red in textile wastewater related industries.

  2. Genetic Diversity of Crimean Congo Hemorrhagic Fever Virus Strains from Iran

    OpenAIRE

    Sadegh Chinikar; Saeid Bouzari; Mohammad Ali Shokrgozar; Ehsan Mostafavi; Tahmineh Jalali; Sahar Khakifirouz; Norbert Nowotny; Fooks, Anthony R.; Nariman Shah-Hosseini

    2016-01-01

    Background: Crimean Congo hemorrhagic fever virus (CCHFV) is a member of the Bunyaviridae family and Nairovirus genus. It has a negative-sense, single stranded RNA genome approximately 19.2 kb, containing the Small, Medium, and Large segments. CCHFVs are relatively divergent in their genome sequence and grouped in seven distinct clades based on S-segment sequence analysis and six clades based on M-segment sequences. Our aim was to obtain new insights into the molecular epidemiology of CCHFV i...

  3. Fatal Chromobacterium violaceum bacteraemia in rural Bandundu, Democratic Republic of the Congo

    Directory of Open Access Journals (Sweden)

    E. Bottieau

    2015-01-01

    Full Text Available We describe the first case of bacteraemia caused by Chromobacterium violaceum in the Democratic Republic of the Congo. This diagnosis was made in an apparently healthy adult who was admitted to a rural hospital of the province of Bandundu with severe community-acquired sepsis. The patient developed multi-organ failure and died; to our knowledge, this is the first reported fatal case in an adult in Africa.

  4. TABOO OF EATING BONOBO AMONG THE BONGANDO PEOPLE IN THE WAMBA REGION, DEMOCRATIC REPUBLIC OF CONGO

    OpenAIRE

    Lingomo, Bongoli; Kimura, Daiji

    2009-01-01

    Among the Bongando, an ethnic group living in and around the village of Wamba, a well-known base for research on the bonobo (Pan paniscus) in the Democratic Republic of Congo, it has traditionally been taboo to eat bonobo. In Bongando folk taxonomy, bonobos are categorized not as animals, but as human beings. The resemblance of bonobo bodily characteristics and behaviors to those of humans is the main reason for this categorization. While this recognition has helped in the conservation of thi...

  5. Isotherm, Kinetic and Thermodynamic Characteristics for Adsorption of Congo Red by Activated Carbon

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jong Jib [Kongju National University, Cheonan (Korea, Republic of)

    2015-02-15

    Batch experiment studies were carried out for adsorption of congo red using granular activated carbon with various parameters such as activated carbon dose, pH, initial dye concentration, temperature and contact time. Equilibrium experimental data are fitted to the Langmuir, Freundlich, Temkin and Dubin-Radushkevich isotherm equations. From Freundlich's separation factor (1/n) estimated, adsorption could be employed as effective treatment method for adsorption of congo red from aqueous solution. Base on Temkin constant (B) and Dubinin-Radushkevich constant (E), this adsorption process is physical adsorption. Adsorption kinetics has been tested using pseudo-first order and pseudo second order models. The results followed pseudo second order model with good correlation. Adsorption process of congo red on granular activated carbon was endothermic (ΔH=42.036 kJ/mol) and was accompanied by decrease in Gibbs free energy (ΔG=-2.414 to -4.596 kJ/mol) with increasing adsorption temperature.

  6. Unstructured-mesh modeling of the Congo river-to-sea continuum

    Science.gov (United States)

    Bars, Yoann Le; Vallaeys, Valentin; Deleersnijder, Éric; Hanert, Emmanuel; Carrere, Loren; Channelière, Claire

    2016-04-01

    With the second largest outflow in the world and one of the widest hydrological basins, the Congo River is of a major importance both locally and globally. However, relatively few studies have been conducted on its hydrology, as compared to other great rivers such as the Amazon, Nile, Yangtze, or Mississippi. The goal of this study is therefore to help fill this gap and provide the first high-resolution simulation of the Congo river-estuary-coastal sea continuum. To this end, we are using a discontinuous-Galerkin finite element marine model that solves the two-dimensional depth-averaged shallow water equations on an unstructured mesh. To ensure a smooth transition from river to coastal sea, we have considered a model that encompasses both hydrological and coastal ocean processes. An important difficulty in setting up this model was to find data to parameterize and validate it, as it is a rather remote and understudied area. Therefore, an important effort in this study has been to establish a methodology to take advantage of all the data sources available including nautical charts that had to be digitalized. The model surface elevation has then been validated with respect to an altimetric database. Model results suggest the existence of gyres in the vicinity of the river mouth that have never been documented before. The effect of those gyres on the Congo River dynamics has been further investigated by simulating the transport of Lagrangian particles and computing the water age.

  7. Shift in the chemical composition of dissolved organic matter in the Congo River network

    Science.gov (United States)

    Lambert, Thibault; Bouillon, Steven; Darchambeau, François; Massicotte, Philippe; Borges, Alberto V.

    2016-09-01

    The processing of terrestrially derived dissolved organic matter (DOM) during downstream transport in fluvial networks is poorly understood. Here, we report a dataset of dissolved organic carbon (DOC) concentrations and DOM composition (stable carbon isotope ratios, absorption and fluorescence properties) acquired along a 1700 km transect in the middle reach of the Congo River basin. Samples were collected in the mainstem and its tributaries during high-water (HW) and falling-water (FW) periods. DOC concentrations and DOM composition along the mainstem were found to differ between the two periods because of a reduced lateral mixing between the central water masses of the Congo River and DOM-rich waters from tributaries and also likely because of a greater photodegradation during FW as water residence time (WRT) increased. Although the Cuvette Centrale wetland (one of the world's largest flooded forests) continuously releases highly aromatic DOM in streams and rivers of the Congo Basin, the downstream transport of DOM was found to result in an along-stream gradient from aromatic to aliphatic compounds. The characterization of DOM through parallel factor analysis (PARAFAC) suggests that this transition results from (1) the losses of aromatic compounds by photodegradation and (2) the production of aliphatic compounds by biological reworking of terrestrial DOM. Finally, this study highlights the critical importance of the river-floodplain connectivity in tropical rivers in controlling DOM biogeochemistry at a large spatial scale and suggests that the degree of DOM processing during downstream transport is a function of landscape characteristics and WRT.

  8. Photocatalytic degradation of Congo red using Carissa edulis extract capped zinc oxide nanoparticles.

    Science.gov (United States)

    Fowsiya, J; Madhumitha, G; Al-Dhabi, Naif Abdullah; Arasu, Mariadhas Valan

    2016-09-01

    The use of plant extract to synthesize nanoparticle has been considered as one of the eco-friendly method. Additionally, it is a strong alternate for conventional methods which includes chemical and physical approach. In this study, microwave assisted extraction of Carissa edulis (C. edulis) at 70°C and 400W was used to extract the secondary metabolites. Further, the metabolites were used as capping agent and Zn (NO3)2 as the metal precursor to synthesize ZnO nanoparticles (ZnO NPs). UV-Vis spectroscopy, FT-IR, XRD, SEM and HR-TEM were used for the characterization of nanoparticles. The Surface Plasmon Resonance around 358nm from the UV-Vis spectroscopy result represents the ZnO NPs formation. The FT-IR confirms the presence of functional groups that acts as the capping agent for the synthesis of ZnO NPs. The crystalline structure of nanoparticles is revealed in the XRD result, morphology showed by SEM results and the size of the ZnO NPs were predicted by HR-TEM. We have carried out the photocatalytic degradation of Congo red at 365nm in photo reactor using ZnO NPs. The result from the photocatalytic degradation Congo red showed rate constant is (-k) 0.4947 with 97% of degradation. This is our first attempt on the C. edulis extract on ZnO NPs preparation and Congo red dye degradation revels that ZnO NPs exhibit good photocatalytic property.

  9. Design and Research of Intelligent Remote Control Fan Based on Single Chip Microcomputer and Bluetooth Technology

    Directory of Open Access Journals (Sweden)

    Zhang Xue-Xia

    2017-01-01

    Full Text Available This paper is designed for intelligent remote control fans. The design of the microcontroller as the core, the sensor, Bluetooth and Andrews system applied to the design of intelligent remote control fan. According to the temperature sensor to achieve the indoor temperature collection, to achieve and set the temperature comparison, thus affecting the fan speed. At the same time, the system according to the infrared sensor components to detect external factors, in order to achieve the running or stopping of the fan, that is, to achieve intelligent control of the fan. In addition, the system achieve the Bluetooth and mobile phone Andrews system of effective combination, and through the software program to complete the fan remote operation and wind speed control.

  10. Numerical simulation of air flow field in high-pressure fan with splitter blades

    Institute of Scientific and Technical Information of China (English)

    Jianfeng LI; Junfu LU; Hai ZHANG; Qing LIU; Guangxi YUE

    2008-01-01

    For a deeper understanding of the flow char-acteristics in the high-pressure centrifugal blower of a fan of Model 9-26 with splitter blades, a three dimensional (3-D) numerical simulation of air flows in the fan was con-ducted with FLUENT software. The standard k-ε tur-bulent model and unstructured grids were used. The computational fluid dynamics (CFD) results showed that the performance of a fan could be improved by adding the splitter blades in the channel among the leaf blades. Under operational conditions, with the presence of splitter blades, the air flow rate of the fan increased about 5% and the total pressure at the outlet of the fan increased about 10% on average. It was also found that the length of the splitter blades affected the air flow and pressure drop. There is an optimal value for the length. The simulation results provide helpful information for improving the fan performance.

  11. Tectonic and climatic controls on fan systems: The Kohrud mountain belt, Central Iran

    Science.gov (United States)

    Jones, Stuart J.; Arzani, Nasser; Allen, Mark B.

    2014-04-01

    Late Pleistocene to Holocene fans of the Kohrud mountain belt (Central Iran) illustrate the problems of differentiating tectonic and climatic drivers for the sedimentary signatures of alluvial fan successions. It is widely recognised that tectonic processes create the topography that causes fan development. The existence and position of fans along the Kohrud mountain belt, NE of Esfahan, are controlled by faulting along the Qom-Zefreh fault system and associated fault zones. These faults display moderate amounts of historical and instrumental seismicity, and so may be considered to be tectonically active. However, fluvial systems on the fans are currently incising in response to low Gavkhoni playa lake levels since the mid-Holocene, producing incised gullies on the fans up to 30 m deep. These gullies expose an interdigitation of lake deposits (dominated by fine-grained silts and clays with evaporites) and coarse gravels that characterise the alluvial fan sediments. The boundaries of each facies are mostly sharp, with fan sediments superimposed on lake sediments with little to no evidence of reworking. In turn, anhydrite-glauberite, mirabilite and halite crusts drape over the gravels, recording a rapid return to still water, shallow ephemeral saline lake sedimentation. Neither transition can be explained by adjustment of the hinterland drainage system after tectonic uplift. The potential influence in Central Iran of enhanced monsoons, the northward drift of the Intertopical Convergence Zone (ITCZ) and Mediterranean climates for the early Holocene (~ 6-10 ka) point to episodic rainfall (during winter months) associated with discrete high magnitude floods on the fan surfaces. The fan sediments were deposited under the general influence of a highstand playa lake whose level was fluctuating in response to climate. This study demonstrates that although tectonism can induce fan development, it is the sensitive balance between aridity and humidity resulting from changes in

  12. Seafloor-precipitated carbonate fans in the Neoproterozoic Rainstorm Member, Johnnie Formation, Death Valley Region, USA

    OpenAIRE

    Pruss, Sara Brady; Corsetti, Frank A.; Fischer, Woodward W.

    2008-01-01

    Cm-sized carbonate seafloor fans occur in the Neoproterozoic Rainstorm Member of the Johnnie Formation, Death Valley, USA. The fans formed in a mixed carbonate-clastic succession near storm wave base at the base of parasequences on a storm-dominated ramp. Petrographic observations indicate that the fans were originally precipitated as aragonite and later inverted to calcite during diagenesis. Although not directly dated, the Rainstorm Member preserves a large magnitude negative carbon isotopi...

  13. Alluvial fan flooding in the Department of Pocito, Province of San Juan, Argentina

    Institute of Scientific and Technical Information of China (English)

    LauraPatriciaPerucca; JuanParedes

    2004-01-01

    The study consists of the identification of landforms subject to alluvial fan flooding in active sectors of the Zonda range piedmont. In the Department of Pocito, located about 5 km southwest of San Juan City, a series of alluvial fans have been identified. These alluvial fans are located downstream of the natural drainage basins covering an area of approximately 130 km2 towards the eastern slopes of the Zonda range at a median elevation of 2,000 m a.s.l.

  14. Quantitative reconstruction of late Holocene surface evolution on an alpine debris-flow fan

    Science.gov (United States)

    Schürch, Peter; Densmore, Alexander L.; Ivy-Ochs, Susan; Rosser, Nick J.; Kober, Florian; Schlunegger, Fritz; McArdell, Brian; Alfimov, Vasili

    2016-12-01

    Debris-flow fans form a ubiquitous record of past debris-flow activity in mountainous areas, and may be useful for inferring past flow characteristics and consequent future hazard. Extracting information on past debris flows from fan records, however, requires an understanding of debris-flow deposition and fan surface evolution; field-scale studies of these processes have been very limited. In this paper, we document the patterns and timing of debris-flow deposition on the surface of the large and exceptionally active Illgraben fan in southwestern Switzerland. We use terrain analysis, radiocarbon dating of sediment fill in the Illgraben catchment, and cosmogenic 10Be and 36Cl exposure dating of debris-flow deposits on the fan to constrain the temporal evolution of the sediment routing system in the catchment and on the fan during the past 3200 years. We show that the fan surface preserves a set of debris-flow lobes that were predominantly deposited after the occurrence of a large rock avalanche near the fan apex at about 3200 years ago. This rock avalanche shifted the apex of the fan and impounded sediment within the Illgraben catchment. Subsequent evolution of the fan surface has been governed by both lateral and radial shifts in the active depositional lobe, revealed by the cosmogenic radionuclide dates and by cross-cutting geometrical relationships on the fan surface. This pattern of frequent avulsion and fan surface occupation provides field-scale evidence of the type of large-scale compensatory behavior observed in experimental sediment routing systems.

  15. Low-pressure reversible axial fan with straight profile blades and relatively high efficiency

    OpenAIRE

    2012-01-01

    The paper presents the design and operating characteristics of a model of reversible axial fan with only one impeller, whose reversibility is achieved by changing the direction of rotation. The fan is designed for the purpose of providing alternating air circulation in wood dryers in order to reduce the consumption of electricity for the fan and increase energy efficiency of the entire dryer. To satisfy the reversibility of flow, the shape of the blade profile is symmetrical along the l...

  16. Multi-objective optimization design and experimental investigation of centrifugal fan performance

    Science.gov (United States)

    Zhang, Lei; Wang, Songling; Hu, Chenxing; Zhang, Qian

    2013-11-01

    Current studies of fan performance optimization mainly focus on two aspects: one is to improve the blade profile, and another is only to consider the influence of single impeller structural parameter on fan performance. However, there are few studies on the comprehensive effect of the key parameters such as blade number, exit stagger angle of blade and the impeller outlet width on the fan performance. The G4-73 backward centrifugal fan widely used in power plants is selected as the research object. Based on orthogonal design and BP neural network, a model for predicting the centrifugal fan performance parameters is established, and the maximum relative errors of the total pressure and efficiency are 0.974% and 0.333%, respectively. Multi-objective optimization of total pressure and efficiency of the fan is conducted with genetic algorithm, and the optimum combination of impeller structural parameters is proposed. The optimized parameters of blade number, exit stagger angle of blade and the impeller outlet width are seperately 14, 43.9°, and 21 cm. The experiments on centrifugal fan performance and noise are conducted before and after the installation of the new impeller. The experimental results show that with the new impeller, the total pressure of fan increases significantly in total range of the flow rate, and the fan efficiency is improved when the relative flow is above 75%, also the high efficiency area is broadened. Additionally, in 65% -100% relative flow, the fan noise is reduced. Under the design operating condition, total pressure and efficiency of the fan are improved by 6.91% and 0.5%, respectively. This research sheds light on the considering of comprehensive effect of impeller structrual parameters on fan performance, and a new impeller can be designed to satisfy the engineering demand such as energy-saving, noise reduction or solving air pressure insufficiency for power plants.

  17. Low-pressure reversible axial fan with straight profile blades and relatively high efficiency

    OpenAIRE

    Spasić Živan T.; Milanović Saša M.; Šušteršič Vanja M.; Nikolić Boban D.

    2012-01-01

    The paper presents the design and operating characteristics of a model of reversible axial fan with only one impeller, whose reversibility is achieved by changing the direction of rotation. The fan is designed for the purpose of providing alternating air circulation in wood dryers in order to reduce the consumption of electricity for the fan and increase energy efficiency of the entire dryer. To satisfy the reversibility of flow, the shape of the blade profile is symmetrical along the l...

  18. Serpentine Diffuser Performance with Emphasis on Future Introduction to a Transonic Fan (Postprint)

    Science.gov (United States)

    2013-01-01

    AFRL-RQ-WP-TP-2014-0168 SERPENTINE DIFFUSER PERFORMANCE WITH EMPHASIS ON FUTURE INTRODUCTION TO A TRANSONIC FAN (POSTPRINT) Chase A...June 2012 – 01 December 2012 4. TITLE AND SUBTITLE SERPENTINE DIFFUSER PERFORMANCE WITH EMPHASIS ON FUTURE INTRODUCTION TO A TRANSONIC FAN...resulting in an overall recovery factor of 0.983. Distortion descriptors are presented and discussed. 15. SUBJECT TERMS diffuser , transonic fan

  19. Descriptive models, grade-tonnage relations, and databases for the assessment of sediment-hosted copper deposits: with emphasis on deposits in the Central Africa Copperbelt, Democratic Republic of the Congo and Zambia: Chapter J in Global mineral resource assessment

    Science.gov (United States)

    Taylor, Cliff D.; Causey, J. Douglas; Denning, Paul D.; Hammarstrom, Jane M.; Hayes, Timothy S.; Horton, John D.; Kirschbaum, Michael J.; Parks, Heather L.; Wilson, Anna B.; Wintzer, Niki E.; Zientek, Michael L.

    2013-01-01

    The Central African Copperbelt (CACB) is one of the most important copper-producing regions of the world. The majority of copper produced in Africa comes from this region defined by the Neoproterozoic Katanga sedimentary basin of the southern Democratic Republic of the Congo (DRC) and northern Zambia. Copper in the CACB is mined from sediment-hosted stratabound copper deposits associated with red beds and includes the giant deposits in the Kolwezi and Tenge-Fungurume districts in the DRC and the Konkola-Musoshi and Nchanga-Chingola districts in Zambia. In recent years, sediment-hosted structurally controlled replacement and vein (SCRV) copper deposits, such as the giant Kansanshi deposit in Zambia have become important exploration targets in the CACB region.

  20. Submarine-fan facies associations of the Eocene Butano Sandstone, Santa Cruz mountains, California

    Science.gov (United States)

    Nilsen, Tor H.

    1984-06-01

    The Eocene Butano Sandstone was deposited as a submarine fan in a relatively small, partly restricted basin in a borderland setting. It is possibly as thick as 3000 m and was derived from erosion of nearly Mesozoic granitic and older metamorphic rocks located to the south. Deposition was at lower bathyal to abyssal water depths. The original fan may have been 120-to 160-km long and 80-km wide. Outcrops of submarine-canyon, innerfan, middle-fan, and outer-fan facies associations indicate that the depositional model of Mutti and Ricci Lucchi can be used to describe the Butano Sandstone.