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Sample records for metallogeny greenstone belt

  1. Tourmaline from the Archean G.R.Halli gold deposit, Chitradurga greenstone belt, Dharwar craton (India): Implications for the gold metallogeny

    OpenAIRE

    Susmita Gupta; Jayananda, M.; Fareeduddin

    2014-01-01

    Tourmaline occurs as a minor but important mineral in the alteration zone of the Archean orogenic gold deposit of Guddadarangavanahalli (G.R.Halli) in the Chitradurga greenstone belt of the western Dharwar craton, southern India. It occurs in the distal alteration halo of the G.R.Halli gold deposit as (a) clusters of very fine grained aggregates which form a minor constituent in the matrix of the altered metabasalt (AMB tourmaline) and (b) in quartz-carbonate veins (vein tourmaline). The vein...

  2. Tourmaline from the Archean G.R.Halli gold deposit, Chitradurga greenstone belt, Dharwar craton (India):Implications for the gold metallogeny

    Institute of Scientific and Technical Information of China (English)

    Susmita Gupta; M. Jayananda; Fareeduddin

    2014-01-01

    Tourmaline occurs as a minor but important mineral in the alteration zone of the Archean orogenic gold deposit of Guddadarangavanahalli (G.R.Halli) in the Chitradurga greenstone belt of the western Dharwar craton, southern India. It occurs in the distal alteration halo of the G.R.Halli gold deposit as (a) clusters of very fine grained aggregates which form a minor constituent in the matrix of the altered metabasalt (AMB tourmaline) and (b) in quartz-carbonate veins (vein tourmaline). The vein tourmaline, based upon the association of specific carbonate minerals, is further grouped as (i) albite-tourmaline-ankerite-quartz veins (vein-1 tourmaline) and (ii) albite-tourmaline-calcite-quartz veins (vein-2 tourmaline). Both the AMB tourmaline and the vein tourmalines (vein-1 and vein-2) belong to the alkali group and are clas-sified under schorl-dravite series. Tourmalines occurring in the veins are zoned while the AMB tour-malines are unzoned. Mineral chemistry and discrimination diagrams reveal that cores and rims of the vein tourmalines are distinctly different. Core composition of the vein tourmalines is similar to the composition of the AMB tourmaline. The formation of the AMB tourmaline and cores of the vein tour-malines are proposed to be related to the regional D1 deformational event associated with the emplacement of the adjoining ca. 2.61 Ga Chitradurga granite whilst rims of the vein tourmalines vis-à-vis gold mineralization is spatially linked to the juvenile magmatic accretion (2.56e2.50 Ga) east of the studied area in the western part of the eastern Dharwar craton.

  3. Is the Cameron River greenstone belt allochthonous?

    Science.gov (United States)

    Kusky, T. M.

    1986-01-01

    Many tectonic models for the Slave Province, N.W.T., Canada, and for Archean granite - greenstone terranes in general, are implicitly dependent on the assumption that greenstone belt lithologies rest unconformably upon older gneissic basement. Other models require originally large separations between gneissic terranes and greenstone belts. A key question relating to the tectonics of greenstone belts is therefore the original spatial relationship between the volcanic assemblages and presumed-basement gneisses, and how this relationship has been modified by subsequent deformation. What remains unclear in these examples is the significance of the so-called later faulting of the greenstone - gneiss contacts. Where unconformities between gneisses and overlying sediments are indisputable, such as at Point Lake, the significance of faults which occur below the base of the volcanic succession also needs to be evaluated. As part of an on-going investigation aimed at answering these and other questions, the extremely well-exposed Cameron River Greenstone Belt and the Sleepy Dragon Metamorphic Complex in the vicinity of Webb Lake and Sleepy Dragon Lake was mapped.

  4. The Ivisartoq Greenstone Belt, Southwest Greenland: New Investigations

    Science.gov (United States)

    Mader, M. M.; Myers, J. S.; Sylvester, P. J.

    2004-05-01

    The Ivisartoq greenstone belt is situated 40 km south of the Isua greenstone belt, within the Archean gneiss complex of southwest Greenland. The Isua region has been the focus of intense study because it contains some of the oldest known (~ 3.8-3.7 Ga) rocks on Earth. However, relatively little research has been conducted within the Ivisartoq belt. The Ivisartoq greenstone belt is exceptionally well-exposed in three dimensions, and primary features are better preserved here than in any other Archean greenstone belt in Greenland. The Ivisartoq greenstone belt provides a unique opportunity to characterise early-middle Archean mafic-ultramafic magmatism. The Ivisartoq greenstone belt forms a southwest-closing, V-shaped synform and was subjected to amphibolite facies metamorphic conditions. New field mapping has concentrated on the 3 km thick southern limb of the synform, where the most complete section of the tectonostratigraphy is preserved, and where pillow structures with unambiguous way-up indicators are observed. The southern limb has been divided into two units of amphibolites: a lower unit and an upper unit. The upper amphibolite unit is characterized by heterogeneously deformed pillow structures interlayered with ultramafic amphibole schists, meta-gabbro, and with boudins of olivine-bearing ultrabasic rocks. The lower amphibolite unit is more heterogenous and intensely deformed than the upper unit. Layers of quartz-feldspathic rocks with sulfides are abundant in both the upper and lower unit and are highly sheared. A thick (~ 500m) section of quartzo-feldspathic gneisses and schists in the lower unit has been the focus of preliminary geochronological work. Previously, only one U/Pb zircon age (~ 2580 Ma from a "paraschist") has been obtained from the Ivisartoq belt and was reported by Baadsgaard in 1976. Currently, laser ablation microprobe inductively coupled plasma - mass spectrometry (LAM ICP-MS) and isotope dilution thermal ionization mass spectrometry

  5. Paleoarchean sulfur cycling : Multiple sulfur isotope constraints from the Barberton Greenstone Belt, South Africa

    NARCIS (Netherlands)

    Montinaro, Alice; Strauss, Harald; Mason, Paul R D; Roerdink, Desiree; Münker, Carsten; Schwarz-Schampera, Ulrich; Arndt, Nicholas T.; Farquhar, James; Beukes, Nicolas J.; Gutzmer, Jens; Peters, Marc

    2015-01-01

    Mass-dependent and mass-independent sulfur isotope fractionation archived in volcanic and sedimentary rocks from the Barberton Greenstone Belt (3550-3215. Ma), South Africa, provide constraints for sulfur cycling on the early Earth. Four different sample suites were studied: komatiites and tholeiite

  6. Sm-Nd dating of Fig Tree clay minerals of the Barberton greenstone belt, South Africa

    Science.gov (United States)

    Toulkeridis, T.; Goldstein, S. L.; Clauer, N.; Kroner, A.; Lowe, D. R.

    1994-01-01

    Sm-Nd isotopic data from carbonate-derived clay minerals of the 3.22-3.25 Ga Fig Tree Group, Barberton greenstone belt, South Africa, form a linear array corresponding to an age of 3102 +/- 64 Ma, making these minerals the oldest dated clays on Earth. The obtained age is 120-160 m.y. younger than the depositional age determined by zircon geochronology. Nd model ages for the clays range from approximately 3.39 to 3.44 Ga and almost cover the age variation of the Barberton greenstone belt rocks, consistent with independent evidence that the clay minerals are derived from material of the belt. The combined isotopic and mineralogical data provide evidence for a cryptic thermal overprint in the sediments of the belt. However, the highest temperature reached by the samples since the time of clay-mineral formation was <300 degrees C, lower than virtually any known early Archean supracrustal sequence.

  7. Aerial geophysics contribution to geology of Crixas Greenstone Belt , Brazil; Contribuicao aerogeofisica a geologia do 'greenstone belt' da Faixa Crixas, Goias, Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Blum, Marcelo de Lawrence Bassay; Rosa, Cassio Thyone A. de; Carmelo, Adriana C.; Souza, Julio Coelho Ferreira de; Pires, Augusto C.B. [Brasilia Univ., DF (Brazil); Araujo, Albano A. de; Carvalho Junior, Osmar A. de [Infosat, XX, World Energy Council (WEC) (Austria)

    1993-07-01

    In this study we present the results obtained by interpreting geophysical data from the Crixas Greenstone Belt area. Magnetic and gamma-ray spectrometric profiles and maps were produced by reprocessing digital data belonging to the Brazil-Canada Geophysical project. Using the very detailed information revealed by the profiles processed in more adequate scale and the lateral continuity supplied by the maps, we obtained a more clear picture of the region. Despite of the strong correlation between profiles and maps with the presently known geology, observed discrepancies indicate targets for geological mapping and mineral exploration. (author)

  8. Geochronology of the Palaeoproterozoic Kautokeino Greenstone Belt, Finnmark, Norway, in its Fennoscandian context

    Science.gov (United States)

    Bingen, Bernard; Solli, Arne; Viola, Giulio; Sverre Sandstad, Jan; Torgersen, Espen; Whitehouse, Martin J.; Skår, Øyvind; Nasuti, Aziz

    2016-04-01

    The northeastern part of the Fennoscandian Shield consists of Archaean cratonic blocks alternating with Palaeoproterozoic greenstone belts ranging in age from c. 2500 to 1950 Ma. Traditionally, the greenstones are interpeted as evidence for rifting of the Archaean continent(s) although it remains unclear whether modern-style oceanic lithosphere developed, followed by a Wilson-cycle-type closure during the Svecokarelian orogeny. Existing geological, isotopic and geochronological data show that the exposed basins hosting the greenstones have distinct lithostratigraphies and geological evolutions and are pericontinental rather than oceanic. A diversity of Palaeoproterozoic mafic mantle derived magmatic rocks show a secular increase of Nd value with time, from EpsilonNd =-2 at 2500 Ma (Shalskiy dikes, Onega, Russia) to EpsilonNd =+4.4 at 2090 Ma (Jouttiaapa basalts, Peräpohja, Finland), suggesting that the regional asthenospheric mantle was less depleted than the model MORB-producing depleted mantle before 2090 Ma. In this work, we report new zircon U-Pb geochronological data in 19 samples from Finnmarkvidda, Norway, to constrain the evolution of the Palaeoproterozoic high-strain Kautokeino Greenstone Belt and its relations with the neighbouring felsic Jergul and Ráiseatnu gneiss complexes. The Jergul complex is an Archaean, low heat flow, TTG cratonic bloc of Karelian affinity formed between 2975 ±10 and 2776 ±6 Ma. The Masi formation, at the base of the Kautokeino Greenstone Belt, is a typical Jatulian quartzite unconformably overlying the Archean basement. An albite-magnetite-rich mafic sill, similar to the Haaskalehto intrusion in Finland, provides a minimum age of 2220 ±7 Ma for the deposition of the quartzite. The Likčá and Čáskejas formations represent the main basaltic volcanism. Direct evidence of an oceanic setting or oceanic suture is lacking. A probably synvolcanic gabbro sill gives an age of 2137 ±5 Ma. Published Sm-Nd whole-rock data on

  9. Geochemistry of Precambrian carbonates: II. Archean greenstone belts and Archean sea water.

    Science.gov (United States)

    Veizer, J; Hoefs, J; Lowe, D R; Thurston, P C

    1989-01-01

    Carbonate rocks with geological attributes of marine sediments are a minor component of the Archean greenstone belts. Despite their relative scarcity, these rocks are important because they record chemical and isotopic properties of coeval oceans. The greenstones containing such carbonates appear to cluster at approximately 2.8 +/- 0.2 and approximately 3.5 +/- 0.1 Ga ago. The samples for the younger group are from the Abitibi, Yellowknife, Wabigoon (Steep Rock Lake), Michipicoten and Uchi greenstone belts of Canada and the "Upper Greenstones" of Zimbabwe. The older group includes the Swaziland Supergroup of South Africa, Warrawoona Group of Australia and the Sargur marbles of India. Mineralogically, the carbonates of the younger greenstones are mostly limestones and of the older ones, ferroan dolomites (ankerites); the latter with some affinities to hydrothermal carbonates. In mineralized areas with iron ores, the carbonate minerals are siderite +/- ankerite, irrespective of the age of the greenstones. Iron-poor dolomites represent a later phase of carbonate generation, related to post-depositional tectonic faulting. The original mineralogy of limestone sequences appears to have been an Sr-rich aragonite. The Archean carbonates yield near-mantle Sr isotopic values, with (87Sr/86Sr)o of 0.7025 +/- 0.0015 and 0.7031 +/- 0.0008 for younger and older greenstones, respectively. The best preserved samples give delta 13C of +1.5 +/- 1.5% PDB, comparable to their Phanerozoic counterparts. In contrast, the best estimate for delta 18O is -7% PDB. Archean limestones, compared to Phanerozoic examples, are enriched in 16O as well as in Mn2+ and Fe2+, and these differences are not a consequence of post-depositional alteration phenomena. The mineralogical and chemical attributes of Archean carbonates (hence sea water) are consistent with the proposition that the composition of the coeval oceans may have been buffered by a pervasive interaction with the "mantle", that is, with

  10. Sulfide Mineralization In The Marble Bar Greenstone Belt Around Mount Edger Batholith, Pilbara Craton, Western Australia

    Science.gov (United States)

    Kitazono, S.; Nedachi, M.; Taguchi, S.

    2004-12-01

    Pilbara Craton is one of the most important regions in the world to understand the evolution of early Earth, because the geological history is well preserved through the metamorphism of low grade. Pilbara Craton, Western Australia, consists of two different tectonic components formed 3.6 and 2.8 Ga; an older Archean granite occupying the east Pilbara and greenstone belt. In the east Pilbara, the most conspicuous structures are broad domal granitoid complex separated by narrow synformal greenstone belts, and a model of continuous lithostratigraphy in the greenstones in which the dominant structures were produced by multi-stage granitoid diapirism. The Marble Bar greenstone belt is distributed around the Mount Edgar of granitoid pluton, and numerous hydrothermal gold veins are distributed in the greenstone near the boundary of pluton. Also base-metal veins and volcanogenic sedimentary type deposits are located in the same area. In this study, we examined the hydrothermal mineralization observed in the core samples of the Marble Bar greenstone belt, drilled at the Salgash area by the Archean Biosphere Drilling Project (ABDP). The Salgash drill hole is composed of tuff breccias with numerous fragments of black shale of 100 m in thickness, alternation of sandstone and shale of 40 m in thickness, basaltic lava and tuff of 30 m in thickness, and shale and sandstone of 110m in thickness with some sills of basalt and ultramafic rock. The rocks had been metamorphosed, and the grade is near the boundary between green schist and amphibolite facies. Low REE content (43 to 88 ppm), low La/Yb ratio (6.3 to 14.3), and high Eu/Eu* ratio (0.9 to 1.3) of the volcanic rocks are ordinal as the basaltic rock in Archean greenstone belts. On the other hand, these rocks show extremely high values of Cr (1500ppm), Ni (700ppm), Co (70 ppm), and Zn (600 ppm). The C isotopic ratios of carbonate in the volcanic rocks are around -3.8 permil. The clastic sediment sandstone and black shale show

  11. An overview of the lithological and geochemical characteristics of the Mesoarchean (ca. 3075) Ivisaartoq greenstone belt, southern West Greenland

    DEFF Research Database (Denmark)

    Polat, A.; Frei, Robert; Appel, P.W.U.

    2008-01-01

    -silicate metasomatism, between 3075 and 2961 Ma. The trace element systematics of the least altered rocks are consistent with a subduction zone geodynamic setting. On the basis of lithological similarities between the Ivisaartoq greenstone belt and Phanerozoic forearc/backarc ophiolites, and intra-oceanic island arcs...

  12. Gold deposits in the late Archaean Nzega-Igunga greenstone belt, central plateau of tanzania

    Energy Technology Data Exchange (ETDEWEB)

    Feiss, P.G.; Siyomana, S.

    1985-01-01

    2.2 m oz of gold have been produced, since 1935, from late Archaean (2480-2740 Ma) greenstone belts of the Central Plateau, Tanzania. North and east of Nzega (4/sup 0/12'S, 3/sup 0/11'E), 18% of the exposed basement, mainly Dodoman schists and granites, consists of metavolcanics and metasediments of the Nyanzian and Kavirondian Series. Four styles of mineralization are observed. 1. Stratabound quartz-gold veins with minor sulfides. Host rocks are quartz porphyry, banded iron formation (BIF), magnetite quartzite, and dense, cherty jasperite at the Sekenke and Canuck mines. The Canuck veins are on strike from BIF's in quartz-eye porphyry of the Igusule Hills. 2. Stratabound, disseminated gold in coarse-grained, crowded feldspar porphyry with lithic fragments and minor pyrite. At Bulangamilwa, the porphyry is conformable with Nyanzian-aged submarine (.) greenstone, volcanic sediment, felsic volcanics, and sericite phyllite. The deposits are on strike with BIF of the Wella Hills, which contains massive sulfide with up to 15% Pb+Zn. 3. Disseminated gold in quartz-albite metasomes in Nyanzian greenstones. At Kirondatal, alteration is associated with alaskites and feldspar porphyry dikes traceable several hundred meters into post-Dodoman diorite porphyry. Gold is with pyrite, arsenopyrite, pyrrhotite, minor chalcopyrite, and sphalerite as well as tourmalinite and silica-cemented breccias. 4. Basal Kavirondian placers in metaconglomerates containing cobbles and boulders of Dodoman and Nyanzian rocks several hundred meters up-section from the stratabound, disseminated mineralization at Bulangamilwa.

  13. Incipient basin inversion of the Middle Archean Moodies Basin, Barberton Supergroup, Barberton Greenstone Belt, South Africa

    Science.gov (United States)

    Kirstein, Jens; Heubeck, Christoph; Lippold, Wigbert

    2010-05-01

    The Moodies Group of the Barberton Greenstone Belt is one of the oldest and best-preserved quartz-rich sedimentary sequences on Earth. Its strata, approx. 3 km thick, record an initial extensional setting, followed by a strong shortening pulse which resulted in the dominant large-scale final deformation of the greenstone belt. We investigated the apparently rapid transition from Moodies extensional to compressive setting through detailed mapping, correlation of measured sections and the analysis of a prominent basaltic lava which extends for approx. 60 km along strike, in order to constrain the tectonic and depositional setting of some of the earliest stable life-providing habitats on Earth. In the middle Moodies Group, large-scale cross-bedded coarse-grained sandstones, interpreted as an offshore dune field, are abruptly overlain by a discontinuous cobble and boulder conglomerate of up to 4 m thickness, possibly representing local small alluvial fans above a cryptic disconformity. A basaltic lava, reaching approx. 50 m thick, regionally exists above this unit and forms the most prominent marker unit in the Moodies Group. In most places, the lava is metasomatically altered to a fine-grained mesh of illite, sericite, chlorite and very fine-grained quartz. In its upper third, it contains abundant amygdules approx. 0.5 - 1 cm in diameter. We did not record significant thickness changes hinting at eruption centers, feeder channels, flow markers nor pillows. Two thin but regionally continuous dacitic tuffs overlying the lava yielded concordant single-zircon ages of 3229+-6 Ma (Heubeck et al., in prep.) which are statistically indistinguishable from underlying Fig Tree Group volcanics and suggest high depositional and subsidence rates (mm/yr or higher) of intervening Moodies Group strata. Overlying clastic sediments up to 1 km thick show a very high lateral and vertical variability in grain size and petrography. Their facies ranges from alluvial conglomeratic wedges

  14. Petrochronology in constraining early Archean Earth processes and environments: Barberton greenstone belt, South Africa

    Science.gov (United States)

    Grosch, Eugene

    2017-04-01

    Analytical and petrological software developments over the past decade have seen rapid innovation in high-spatial resolution petrological techniques, for example, laser-ablation ICP-MS, secondary ion microprobe (SIMS, nano-SIMS), thermodynamic modelling and electron microprobe microscale mapping techniques (e.g. XMapTools). This presentation will focus on the application of petrochronology to ca. 3.55 to 3.33 billion-year-old metavolcanic and sedimentary rocks of the Onverwacht Group, shedding light on the earliest geologic evolution of the Paleoarchean Barberton greenstone belt (BGB) of South Africa. The field, scientific drilling and petrological research conducted over the past 8 years, aims to illustrate how: (a) LA-ICP-MS and SIMS U-Pb detrital zircon geochronology has helped identify the earliest tectono-sedimentary basin and sediment sources in the BGB, as well as reconstructing geodynamic processes as early as ca. 3.432 billion-years ago; (b) in-situ SIMS multiple sulphur isotope analysis of sulphides across various early Archean rock units help to reconstruct atmospheric, surface and subsurface environments on early Archean Earth and (c) the earliest candidate textural traces for subsurface microbial life can be investigated by in-situ LA-ICP-MS U-Pb dating of titanite, micro-XANES Fe-speciation analysis and metamorphic microscale mapping. Collectively, petrochronology combined with high-resolution field mapping studies, is a powerful multi-disciplinary approach towards deciphering petrogenetic and geodynamic processes preserved in the Paleoarchean Barberton greenstone belt of South Africa, with implications for early Archean Earth evolution.

  15. Geochemistry of the Neoarchaean Volcanic Rocks of the Kilimafedha Greenstone Belt, Northeastern Tanzania

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    Charles W. Messo

    2012-01-01

    Full Text Available The Neoarchaean volcanic rocks of the Kilimafedha greenstone belt consist of three petrological types that are closely associated in space and time: the predominant intermediate volcanic rocks with intermediate calc-alkaline to tholeiitic affinities, the volumetrically minor tholeiitic basalts, and rhyolites. The tholeiitic basalts are characterized by slightly depleted LREE to nearly flat REE patterns with no Eu anomalies but have negative anomalies of Nb. The intermediate volcanic rocks exhibit very coherent, fractionated REE patterns, slightly negative to absent Eu anomalies, depletion in Nb, Ta, and Ti in multielement spidergrams, and enrichment of HFSE relative to MORB. Compared to the other two suites, the rhyolites are characterized by low concentrations of TiO2 and overall low abundances of total REE, as well as large negative Ti, Sr, and Eu anomalies. The three suites have a εNd (2.7 Ga values in the range of −0.51 to +5.17. The geochemical features of the tholeiitic basalts are interpreted in terms of derivation from higher degrees of partial melting of a peridotite mantle wedge that has been variably metasomatized by aqueous fluids derived from dehydration of the subducting slab. The rocks showing intermediate affinities are interpreted to have been formed as differentiates of a primary magma formed later by lower degrees of partial melting of a garnet free mantle wedge that was strongly metasomatized by both fluid and melt derived from the subducting oceanic slab. The rhyolites are best interpreted as having been formed by shallow level fractional crystallization of the intermediate volcanic rocks involving plagioclase and Ti-rich phases like ilmenite and magnetite as well as REE-rich phases like apatite, zircon, monazite, and allanite. The close spatial association of the three petrological types in the Kilimafedha greenstone belt is interpreted as reflecting their formation in an evolving late Archaean island arc.

  16. Stratigraphy and geochronlogy of the Guarinos greenstone belt, Goiás, Brazil

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    Hardy Jost

    2012-08-01

    Full Text Available The Guarinos greenstone belt is one of the three low metamorphic grade supracrustal rocks assemblage rimmed by orthogneissesof Central Brazil’s Archean Block northern limits. The investigation of the stratigraphy of those greenstone beltsstarted by the end of 1970’s and underwent improvements during the years as a result of detailed geological mapping. Thelatest and accepted stratigraphic model for the Guarinos greenstone belt refers its supracrustal rocks under the GuarinosGroup, which is subdivided into the Serra do Cotovelo (metakomatiites, Serra Azul (metabasalts, São Patricinho (maficmetaturbidites, Aimbé (BIF and Cabaçal (carbonaceous phyllites and impure metarenites formations. Detailed geologicmapping (1:10,000 and drill-cores during an exploration program by Yamana Desenvolvimento Mineral S.A. in the areaallowed a better definition of the metasedimentary package of the Cabaçal Formation, which is here formally proposed tobe subdivided into a Lower Member of carbonaceous phyllites with basalt lava flows and gondite lenses interlayers, anIntermediate Member of gondite, iron formation, metachert and massive barite lenses, and an Upper Member of carbonaceous phyllites with minor metachert lenses. The impure metarenites, formerly considered as part of the Cabaçal Formation, are proposedunder the Mata Preta Formation, which is laterally interfingered with the Cabaçal Formation. U-Pb LA-ICP-MS geochronologicaldata of detrital zircon grains from the São Patricinho mafic metaturbidites and the impure metarenites of the Mata Preta formationsindicate that the major source-area of the clastic load had a Siderian to Rhyacian age, with minor contribution from Archean rocks.From the rock assemblage of both units and their contact relationships it is concluded that the basin stage they represent evolved duringthe world-wide Anoxic Oceanic Event (AOE that took place during the 2.2 to 2.06 Ga, represented by the carbonaceous phyllites ofthe

  17. Micro-XRF Analysis of Archean Spherule Layers and Host Rocks from the CT3 Drill Core, Barberton Greenstone Belt, South Africa

    Science.gov (United States)

    Hoehnel, D.; Tagle, R.; Hofmann, A.; Reimold, W. U.; Mohr-Westheide, T.; Fritz, J.; Altenberger, U.

    2016-08-01

    Spherule layers and host rock samples from the Barberton Greenstone Belt were studied with a µ-XRF spectrometer. Elemental distribution maps indicate distinct folding that had been recognized neither by visual inspection nor by petrographic analysis.

  18. Archaean Greenstone Belt Architecture and Stratigraphy: are Comparisons With Ophiolites and Oceanic Plateaux Valid?

    Science.gov (United States)

    Bedard, J. H.; Bleeker, W.; Leclerc, F.

    2005-12-01

    Archaean greenstone belts and coeval plutonic belts (dominated by TTGs, tonalite-tronhjemite-granodiorite), are commonly interpreted to represent assembled fragments of oceanic crust, oceanic plateaux or juvenile arc terranes, variably reworked by Archaean orogenic processes related to the operation of plate tectonics. However, many of the lava successions that have been interpreted to represent accreted oceanic plateaux are demonstrably ensialic, can be correlated over long distances along-strike, have depositional contacts onto older continental crustal rocks, show tholeiitic to calc-alkaline cyclicity, and have isotopic signatures indicating assimilation of older felsic crust. Inferred Archaean ophiolites do not have sheeted dyke complexes or associated mantle rocks, and cannot be proven to be oceanic terranes formed by seafloor-spreading. Archaean supracrustal sequences are typically dominated by tholeiitic to komatiitic lavas, typically interpreted to represent the products of decompression melting of mantle plumes. Subordinate proportions of andesites, dacites and rhyolites also occur, and these, together with the coeval TTGs, are generally interpreted to represent arc magmas. In the context of uniformitarian interpretations, the coeval emplacement of putative arc- and plume-related magmas requires extremely complex geodynamic scenarios. However, the relative rarity of the archetypal convergent margin magma type (andesite) in Archaean sequences, and the absence of Archaean blueschists, ultra-high-pressure terranes, thrust and fold belts, core complexes and ophiolites, along with theoretical arguments against Archaean subduction, together imply that Archaean cratonic crust was not formed through uniformitarian plate-tectonic processes. A simpler interpretation involves soft intraoceanic collisions of thick (30-50km), plume-related, basaltic-komatiitic oceanic plateaux, with ongoing mafic magmatism leading to anatexis of the hydrated plateau base to generate

  19. Thermal implications of metamorphism in greenstone belts and the hot asthenosphere-thick continental lithoshere paradox

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    Morgan, P.

    1986-01-01

    From considerations of secular cooling of the Earth and the slow decay of radiogenic heat sources in the Earth with time, the conclusion that global heat loss must have been higher in the Archean than at present seems inescapable. The mechanism by which this additional heat was lost and the implications of higher heat low for crustal temperatures are fundamental unknowns in our current understanding of Archean tectonics and geological processes. Higher heat loss implies that the average global geothermal gradient was higher in the Archean than at present, and the restriction of ultramafic komatiites to the Archean and other considerations suggests that the average temperature of the mantle was several hundred degrees hotter during the Archean than today. In contrast, there is little petrologic evidence that the conditions of metamorphism or crustal thickness (including maximum crustal thickness under mountains) were different in archean continental crust from the Phanerozoic record. Additionally, Archean ages have recently been determined for inclusions in diamonds from Cretaceous kimeberlites in South Africa, indicating temperatures of 900 to 1300 at depths of 150 to 215 km (45 to 65 kbar) in the Archean mantle, again implying relatively low geothermal gradients at least locally in the Archean. The thermal implications of metamorphism are examined, with special reference to greenstone belts, and a new thermal model of the continental lithosphere is suggested which is consistent with thick continental lithosphere and high asthenosphere temperatures in the Archean.

  20. Rare earth element geochemical constrains on metallogeny of Jiapigou gold belt, Northeast China

    Institute of Scientific and Technical Information of China (English)

    HUANG Zhixin; YUAN Wanming; YU Haijun

    2012-01-01

    Analyses of rare earth dements (REE) in gold-bearing quartz vein,granite and altered wall-rock (amphibolite) collected from Jiapigou gold belt in Southeast Jilin Province were conducted using inductively coupled plasma-mass-spectrometry (ICP-MS).The results indicated that the Jiapigou gold belt underwent two periods of gold mineralization:the earlier mineralization was related to the intrusion of Neoarchaean kaligranite,where the REE of earlier gold-bearing quartz veins and Neoarchaean kaligranites were typically featured by lower concentration and positive Eu anomaly; the later mineralization was related to the intrusion of the Yanshanian granite in Mesozoic,where the REE of later gold-bearing quartz veins and Yanshanian granites were typically featured by high concentration and negative Eu anomaly.However,the metallogenic mechanisms of the earlier and of the later gold mineralization periods were analogous,metallogenic materials were heterogenous with metallogenic fluids which mainly originated from magmatic hydrothermal fluids,mixed with metamorphic fluids; the metallogenic materials were mainly derived from the altered wall rock.

  1. Banatitic magmatic and metallogenetic belt: metallogeny of the Romanian Carpathians segment

    Directory of Open Access Journals (Sweden)

    S̡erban-Nicolae Vlad

    2003-04-01

    Full Text Available The Romanian Carpathians sector of the Late Cretaceous Banatitic Magmatic and Metallogenetic belt (BMMB contains 1 plutons and volcano-plutonic complexes, i. e. calc-alkaline, I-type granitoids, with related ores; 2 shoshonitic plutons that lack economic interest. Two provinces have been delineated: the Apuseni Mts. Province in the North and the Western South Carpathians in the South. Apuseni Mts. Province is a non-porphyry environment related to more evolved (granodioritic-granitic magmatism. It is subdivided into three zones: Vlădeasa (Pb-Zn ores of restricted metallogenetic potential; Gilău-Bihor (Fe, Bi, Mo, Cu, W, Au, Ni, Co, Pb, Zn, Ag, U, B ores / conspicuous peri-batholitic arrangement and South Apuseni (only one minor Fe-skarn occurrence. Western South Carpathians Province occurs in Romania and extends in Eastern Serbia. It is subdivided into South Banat Mts.–Timok Zone (SBTZ and Poiana Ruscă Mts.– North Banat Mts.– Ridanj-Krepoljin Zone (PR-NB-RKZ. SBTZ is a typical porphyry environment of high metallogenetic potential (Cu, Au, Pb, Zn, while PR-NB-RKZ is a non-porphyry environment with small to medium size Pb, Zn, Fe, Cu deposits/prospects exhibiting commonly a peri-plutonic zoning. The metallogenetic model of the Romanian Carpathians segment of BMMB is conceived based on correlating magma composition/level of emplacement and ore types.

  2. Multistage gold mineralization in the Wa-Lawra greenstone belt, NW Ghana: The Bepkong deposit

    Science.gov (United States)

    Amponsah, Prince Ofori; Salvi, Stefano; Didier, Béziat; Baratoux, Lenka; Siebenaller, Luc; Jessell, Mark; Nude, Prosper Mackenzie; Gyawu, Eugene Adubofour

    2016-08-01

    The Bepkong gold deposit is one of several gold camps in the Paleoproterozoic Wa-Lawra greenstone belt in northwest Ghana. These deposits lay along the Kunche-Atikpi shear zone, which is part of the larger transcurrent Jirapa shear zone. The formation of these shear zones can be attributed to the general ESE-WNW major shortening that took place in the Wa-Lawra belt. Gold mineralization in the Bepkong deposit mainly occurs within graphitic shales and volcaniclastic rocks. The ore consists of four N-S trending lenticular bodies, plunging steeply to the south, that are lithologically and structurally controlled. Their shape and thickness are variable, though a general strike length of 560 m and an overall thickness of 300 m can be defined. An alteration mineral assemblage characterises the ore, and consists of chlorite-calcite-sericite-quartz-arsenopyrite-pyrite. Pyrite, as distinct from arsenopyrite, is not limited to the altered rocks and occurs throughout the area. At Bepkong, gold is associated with arsenopyrite and pyrite, which occur disseminated in the mineralized wall rock, flanking Type-1 quartz veins, or within fractures crossing these veins. Textural observations indicate the early formation of abundant arsenopyrite, followed by pyrite, with chalcopyrite, galena, sphalerite and pyrrhotite occurring as inclusions within pyrite and altered arsenopyrite. Detailed petrography, coupled with SEM, LA-ICP-MS and EMP analyses, indicate that gold in the Bepkong deposit occurs in three distinct forms: (i) invisible gold, mostly in arsenopyrite (ii); visible gold as micron-size grains within fractures and altered rims of arsenopyrite, as well as at the interface of sulphide grains; (iii) free visible gold in fractures in quartz veins and their selvages. We interpret the invisible gold to have co-precipitated with the early-formed arsenopyrite. The small visible gold grains observed within the sulphide interfaces, altered arsenopyrite, fractures and grain boundaries

  3. Physical volcanology of the mafic segment of the subaqueous New Senator caldera, Abitibi greenstone belt, Quebec, Canada

    Energy Technology Data Exchange (ETDEWEB)

    Moore, Lyndsay N; Mueller, Wulf U [Universite du Quebec a Chicoutimi, 555 boul. du l' Universite, Chicoutimi, Quebec, G7H2B1 (Canada)], E-mail: lyndsay.moore@uqac.ca

    2008-10-01

    Archean calderas provide valuable insight into internal geometries of subaqueous calderas. The New Senator caldera, Abitibi greenstone belt, Canada, is an Archean example of a subaqueous nested caldera with a basal stratigraphy dominated by gabbro-diorite dykes and sills, ponded magmas and basalt and andesite lava flows. The aim of our study is to focus on the use of physical volcanology to differentiate between the various mafic units found at the base of the New Senator caldera. Differentiation between these various mafic units is important from an exploration point of view because in modern subaqueous summit calders (e.g. Axial Seamount) margins of ponded magmas are often sites of VMS formation.

  4. Evidence for spreading in the lower Kam Group of the Yellowknife greenstone belt: Implications for Archaean basin evolution in the Slave Province

    Science.gov (United States)

    Helmstaedt, H.; Padgham, W. A.

    The Yellowknife greenstone belt is the western margin of an Archean turbidite-filled basin bordered on the east by the Cameron River and Beaulieu River volcanic belts (Henderson, 1981; Lambert, 1982). This model implies that rifting was entirely ensialic and did not proceed beyond the graben stage. Volcanism is assumed to have been restricted to the boundary faults, and the basin was floored by a downfaulted granitic basement. On the other hand, the enormous thickness of submarine volcanic rocks and the presence of a spreading complex at the base of the Kam Group suggest that volcanic rocks were much more widespread than indicated by their present distribution. Rather than resembling volcanic sequences in intracratonic graben structures, the Kam Group and its tectonic setting within the Yellowknife greenstone belt have greater affinities to the Rocas Verdes of southern Chile, Mesozoic ophiolites, that were formed in an arc-related marginal basin setting. The similarities of these ophiolites with some Archean volcanic sequences was previously recognized, and served as basis for their marginal-basin model of greenstone belts. The discovery of a multiple and sheeted dike complex in the Kam Group confirms that features typical of Phanerozoic ophiolites are indeed preserved in some greenstone belts and provides further field evidence in support of such a model.

  5. Volcanic-hosted massive sulfide deposits in the Murchison greenstone belt, South Africa

    Science.gov (United States)

    Schwarz-Schampera, Ulrich; Terblanche, Hennie; Oberthür, Thomas

    2010-02-01

    The Archean Murchison greenstone belt, Limpopo Province, South Africa, represents a rifted epicontinental arc sequence containing the largest volcanic-hosted massive sulfide (VMS) district in Southern Africa. The so-called Cu-Zn line is host to 12 deposits of massive sulfide mineralization including: Maranda J, LCZ, Romotshidi, Mon Desir, Solomons, and Mashawa with a total tonnage of three million metric tons of very high grade Zn, subordinate Cu, and variable Pb and Au ore. The deposits developed during initial phases of highly evolved felsic volcanism between 2,974.8 ± 3.6 and 2,963.2 ± 6.4 Ma and are closely associated with quartz porphyritic rhyolite domes. Elevated heat supply ensured regional hydrothermal convection along the entire rift. Recurrent volcanism resulted in frequent disruption of hydrothermal discharge and relative short-lived episodes of hydrothermal activity, probably responsible for the small size of the deposits. Stable thermal conditions led to the development of mature hydrothermal vent fields from focused fluid discharge and sulfide precipitation within thin layers of felsic volcaniclastic rocks. Two main ore suites occur in the massive sulfide deposits of the “Cu-Zn line”: (1) a low-temperature venting, polymetallic assemblage of Zn, Pb, Sb, As, Cd, Te, Bi, Sn, ±In, ±Au, ±Mo occurring in the pyrite- and sphalerite-dominated ore types and (2) a higher temperature suite of Cu, Ag, Au, Se, In, Co, Ni is associated with chalcopyrite-bearing ores. Sphalerite ore, mineralogy, and geochemical composition attest to hydrothermal activity at relatively low temperatures of ≤250 °C for the entire rift, with short-lived pulses of higher temperature upflow, reflected by proportions of Zn-rich versus Cu-rich deposits. Major- and trace-metal composition of the deposits and Pb isotope signatures reflect the highly evolved felsic source rock composition. Geological setting, host rock composition, and metallogenesis share many similarities not

  6. Origin of Peculiar Horizons from the Nuvvuagittuq Greenstone Belt: Testing the Conglomerate Hypothesis

    Science.gov (United States)

    Kitayama, C.; Thomassot, E.; Wing, B. A.

    2009-05-01

    Earth's earliest rock record is fragmentary, and often distorted by metamorphic changes suffered under great temperatures and pressures. Recent work may, however, have opened the door to more direct examination of the earliest Earth. Measurements of Nd-142 from rocks of the Nuvvuagittuq Greenstone Belt (NGB), N. Quebec yield an apparent 4.28 Ga isochron (O'Neil et al., 2008). These are potentially the oldest rocks on Earth and understanding the protoliths of the rocks of the NGB may help constrain Earth's earliest surface environment. Peculiar horizons of quartz-rich rocks within the NGB have been hypothesized to represent metamorphosed conglomerates. In order to evaluate this hypothesis, we apply a series of consistency tests aimed at observations ranging from the field to microscale. First, we made high-resolution (10m grid) maps of the purported conglomerate horizons, and interpreted the map pattern of these horizons for their conformity with sedimentary contacts. The horizons are continuous throughout the mapped area, and do not cross cut any other lithologies, which is necessary, but not sufficient, evidence for a sedimentary origin. Second, we examined the mineralogy and three-dimensional geometry of the potential clasts in large polished blocks. The potential clasts fall into just two different types: the dominant type is made up primarily of coarse grains of quartz; the second type is distinctly subordinate and is largely made up of fine-grained equigranular quartz and relict plagioclase with minor amounts of biotite. The dominant type can occur as lozenge-shaped pods up to 5 cm thick, while the subordinate type more commonly occurs as thin (<2 cm thick) undulose layers. Neither the mineralogies nor the geometries of the potential clasts offer certain indication of a sedimentary origin, though they are potentially consistent with one. Third, we are comparing the identity and chemistry of trace minerals within the potential clasts to that of the surrounding

  7. Study of Carbonaceous Material in cherts from Barberton Greenstone Belt and the Astrobiological Implications.

    Science.gov (United States)

    Rull, F.; Venegas, G.; Montero, O.; Medina, J.

    2012-04-01

    Carbonaceous matter is present in chert deposits of Barberton Greenstone Belt (BGB), South Africa. This is a famous place in the world for its Archean geology, wich represents around 3.5 billion years of earth's history. Therefore this area provides us the opportunity to study and understand an important part history of our planet, and also allow to compare with the geological history of other planets in our solar system [1]. Raman micro-spectroscopy has proved to be a very important and non-destructive powerful tool for distinguish micro-sized particles of C-polymorphs, as it is very sensitive to the nature of carbon bonding [2]. The connection between the Raman characterization of these carbonaceous phases with ancient biogenic activity it's of special interest. Cherts of BGB have been interpreted as precipitates or diagenetic replacements of preexisting sedimentary and pyroclastic deposits in a silica saturated Archean ocean [3]. Several layered Samples of cherts from BGB utility for the present study were collected during the expedition carried out in August 2010 sponsored by CNES and ESA. A detailed Raman spectral analysis of carbon C-C vibrations has been performed in the first (1200-1800 cm-1) and second (2500-3200 cm-1) order regions [4]. The results show important changes in the G-D bands in the layered structure of chert. Additionally a UPLC-ESI-QTOF-MS was carried out trying to introduce new insight in the Raman interpretation of the bands and in the possible assignments to particular molecular groups which could be related with biotic or abiotic origin of the carbonaceous material. Among the tentative compounds obtained from UPLC-ESI-QTOF-MS study it is worth to mention hydroxy-lycopene and the hydroxyl derivative of β-carotene (i.e. β-cryptoxanthin), which are carotenoids produced by cyanobacteria. These results are consistent with the presence of 22-Hopanol and Tetrahymanol, which are characteristic hopanoids of photosynthetic cyanobacteria and have

  8. The Fazenda Gavião granodiorite and associated potassic plutons as evidence for Palaeoproterozoic arc-continent collision in the Rio Itapicuru greenstone belt, Brazil

    Science.gov (United States)

    Costa, Felipe G.; Oliveira, Elson P.; McNaughton, Neal J.

    2011-08-01

    Several granitic plutons have intruded the Palaeoproterozoic Rio Itapicuru greenstone belt, São Francisco craton, Brazil, in the time interval 2163-2080 Ma, but their tectonic significance is poorly understood. The Fazenda Gavião granodiorite (FGG) is one of a set of plutons emplaced along the western boundary of the greenstone belt with Archaean migmatite-gneiss basement. The pluton is mostly composed of hornblende granodiorite, occasionally crosscut by syn-plutonic mafic dykes. The FGG is metaluminous, medium- to high-K calc-alkaline with relatively constant silica abundances (SiO2 ˜ 63-66 wt%), high Sr (900-800 ppm) and high Ba (1000-1500 ppm). The associated mafic dykes are ultrapotassic, with high abundances of Ba, Sr, MgO, Ni, Cr, and light rare earth elements, suggesting derivation from partial melts of an enriched mantle source. The FGG originated probably by fractional crystallization from a primitive K-rich mafic magma that interacted with crustal melts. Its zircon U-Pb SHRIMP age of 2106 ± 6 Ma indicates that the FGG is younger than the early (2163-2127 Ma) tonalite-trondhjemite-granodiorite (TTG) and calc-alkaline arc plutons of the greenstone belt, and is closely related in time and space with potassic to ultrapotassic plutons (ca. 2110-2105 Ma). The negative ɛNd(t) of FGG and coeval K-rich plutons of the Rio Itapicuru greenstone belt contrasts markedly with the positive ɛNd(t) of the older arc plutons, indicating a major change of isotope signatures in granites of the Rio Itapicuru greenstone belt with time. This isotope shift may be related to magma contamination with older continental material and/or derivation of the parental potassic magma from enriched lithospheric mantle sources. We suggest that the K-rich plutons were emplaced during or shortly after Palaeoproterozoic arc-continent collision.

  9. Source heterogeneity for the major components of ~3.7 Ga banded iron formations (Isua Greenstone Belt, Western Greenland)

    DEFF Research Database (Denmark)

    Frei, Robert; Polat, Ali

    2006-01-01

    We report trace element, samarium (Sm)-neodymium (Nd) and lead (Pb) isotopic data for individual micro-and mesobands of the Earth's oldest Banded Iron Formation (BIF) from the  3.7-3.8 Ga Isua Greenstone Belt (IGB, West Greenland) in an attempt to contribute to the characterization...... low high field strength elements (HFSE) concentrations indicate essentially detritus-free precipitation. Uranogenic Pb isotope data define a correlation line with a slope of 3691 ± 41 Ma, indicating that the uranium (U)-lead (Pb) system remained closed after the formation of this BIF. High 207Pb/204Pb...... relative to 206Pb/204Pb ratios compared to average mantle growth evolution models are a feature shared by BIF, penecontemporaneous basalts and clastic volcanogenic metasediments and are indicative of the ultimate high-µ (238U/204Pb) character of the source region, an essentially mafic Hadean protocrust. Sm...

  10. Potential of thermal emissivity for mapping of greenstone rocks and associated granitoids of Hutti Maski Schist belt, Karnataka

    Science.gov (United States)

    Guha, A.; Vinod Kumar, K.

    2014-11-01

    In the present study, different temperature-emissivity separation algorithms were used to derive emissivity images based on processing of ASTER( Advanced spaceborne thermal emission and reflection radiometer) thermal bands. These emissivity images have been compared with each other in terms of geological information for mapping of major rock types in Hutti Maski schist Belt and its associated granitoids. Thermal emissivity images are analyzed conjugately with thermal radiance image, radiant temperature image and albedo image of ASTER bands to understand the potential of thermal emissivity in delineating different rock types of Archaean Greenstone belt. The emissivity images derived using different emissivity extraction algorithms are characterised with poor data dimensionality and signal to noise ratio. Therefore, Inverse MNF false-colour composites(FCC) are derived using bands having better signal to noise(SNR)ratio to enhance the contrast in emissivity. It has been observed that inverse-MNF of emissivity image; which is derived using emissivity-normalisation method is suitable for delineating silica variations in granite and granodioritic gneiss in comparison to other inverse- MNF-emissivity composites derived using other emissivity extraction algorithms(reference channel and alpha residual method). Based on the analysis of ASTER derived emissivity spectra of each rocks, band ratios are derived(band 14/12,band 10/12) and these ratios are used to delineate the rock types based on index based FCC image. This FCC image can be used to delineate granitoids with different silica content. The geological information derived based on processing of ASTER thermal images are further compared with the image analysis products derived using ASTER visible-near-infrared(VNIR) and shortwave infrared(SWIR) bands. It has been observed that delineation of different mafic rocks or greenstone rocks(i.e. separation between chlorite schist and metabasalt) are better in SWIR composites

  11. Uranium Potential and Regional Metallogeny in China

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jindai; LI Ziying

    2008-01-01

    This paper is briefly involved in distributions of China's uranium metallogenic types,provinces, regions and belts. Eight target regions have been pointed out to be worthy of prospectingfor uranium resources. The regional uranium metallogeny is discussed and great uranium potentialpointed out from many aspects. Generally speaking, there are favorable conditions for uraniummineralization and good perspective to explore for uranium resources.

  12. Tectono-magmatic evolution of the Hutti-Maski Greenstone Belt, India: Constrained using geochemical and geochronological data

    Science.gov (United States)

    Rogers, A. J.; Kolb, J.; Meyer, F. M.; Armstrong, R. A.

    2007-08-01

    The Hutti-Maski Greenstone Belt (HMGB), situated in the eastern block of the Dharwar Craton, India is dominated by bimodal volcanics with a minimum magmatic age of 2586 ± 59 Ma. Two phases of granitoid intruded into the belt, the syn-tectonic Kavital granitoid, homogeneous, medium-grained porphyritic granodiorite, with an intrusion age of 2543 ± 9 Ma, followed by the post-tectonic Yelagatti granitoid, heterogeneous, fine- to medium-grained granite to granodiorite. The extensively altered zircons from the Yelagatti granitoid have significant enrichments of U, Th (>1%) and common-Pb (up to 47%). Only two of the analyses were reproducible, providing a minimum 207Pb/ 206Pb age of 2221 ± 99 Ma, this may indicate an approximate magmatic age or more realistically a subsequent event. Felsic metavolcanic rocks contain cross-cutting veinlets, which formed during the Mesoproterozoic (ca. 1180 Ma), the final closure of the Pb system occurred between the Neoproterozoic and Ordovician, possibly related to the Pan-African orogeny. The tectono-magmatic evolution of the HMGB can be correlated with the collision between the eastern and western blocks of the Dharwar Craton subsequent to 2658 Ma and the craton wide magmatism from 2613 to 2513 Ma. These events can be accounted for by combining uniformitarian and non-uniformitarian models.

  13. The discovery of the Neoarchean mafic dyke swarm in Hengshan and reinterpretation of the previous "Wutai greenstone belt"

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The structural mapping and section study indicate that the "greenstone belts" in the southern to central parts of Hengshan were intensively sheared and transposed mafic dyke swarm,which originally intruded into the Neoarchean grey gneiss and high-pressure granulite terrain(HPGT).The HPGT is characterized by flat-dipping structures,to the south it became steep and was cut by the Dianmen mafic dyke swarm.After high-pressure granulite-facies metamorphic event,the mafic dyke swarm occurred,and was associated with the extensional setting and reworked by the late strike-slip shearing.The zircon age dating proves that the Dianmen mafic dyke swarm was emplaced during the period between 2499±4 Ma and 2512±3 Ma,followed by late tectonothermal reworking.The Dianmen mafic dyke swarm further documents the extensional episode in the central to northern parts of North China Craton(NCC),providing the important constraint for the limit between Archean and Proterozoic and correlation between NCC and other cratonic blocks of the world.

  14. Geochemistry of komatiites and basalts from the Rio das Velhas and Pitangui greenstone belts, São Francisco Craton, Brazil: Implications for the origin, evolution, and tectonic setting

    Science.gov (United States)

    Verma, Sanjeet K.; Oliveira, Elson P.; Silva, Paola M.; Moreno, Juan A.; Amaral, Wagner S.

    2017-07-01

    The Neoarchean Rio das Velhas and Pitangui greenstone belts are situated in the southern São Francisco Craton, Minas Gerais, Brazil. These greenstone belts were formed between ca. 2.79-2.73 Ga, and consist mostly of mafic to ultramafic volcanics and clastic sediments, with minor chemical sediments and felsic volcanics that were metamorphosed under greenschist facies. Komatiites are found only in the Rio das Velhas greenstone belt, which is composed of high-MgO volcanic rocks that have been identified as komatiites and high-Mg basalts, based on their distinctive geochemical characteristics. The Rio das Velhas komatiites are composed of tremolite + actinolite + serpentine + albite with a relict spinifex-texture. The Rio das Velhas komatiites have a high magnesium content ((MgO)adj ≥ 28 wt.%), an Al-undepleted Munro-type [(Al2O3/TiO2)adj and (CaO/Al2O3)adj] ratio ranging from 27 to 47 and 0.48 to 0.89, relatively low abundances of incompatible elements, a depletion of light rare earth elements (LREE), a pattern of non-fractionated heavy rare- earth elements (HREE), and a low (Gd/Yb)PM ratio (≤ 1.0). Negative Ce anomalies suggest that alteration occurred during greenschist facies metamorphism for the komatiites and high-Mg basalts. The low [(Gd/Yb)PM 18] and high HREE, Y, and Zr content suggest that the Rio das Velhas komatiites were derived from the shallow upper mantle without garnet involvement in the residue. The chemical compositions [(Al2O3/TiO2)adj, (FeO)adj, (MgO)adj, (CaO/Al2O3)adj, Na, Th, Ta, Ni, Cr, Zr, Y, Hf, and REE] indicate that the formation of the komatiites, high-Mg basalts and basalts occurred at different depths and temperatures in a heterogeneous mantle. The komatiites and high-Mg basalts melted at liquidus temperatures of 1450-1550 °C. The Pitangui basalts are enriched in the highly incompatible LILE (large-ion lithophile elements) relative to the moderately incompatible HFS (high field strength) elements. The Zr/Th ratio ranging from 76 to

  15. A Detailed Record of Archean Biogochemical Cycles and Seawater Chemistry Preserved in Black Shales of the Abitibi Greenstone Belt

    Science.gov (United States)

    Scott, C.; Planavsky, N. J.; Bates, S. M.; Wing, B. A.; Lyons, T. W.

    2011-12-01

    Geological and biological evolution are intimately linked within the Earth System through the medium of seawater. Thus, in order to track the co-evolution of Life and Earth during the Archean Eon we must determine how biogeochemical cycles responded to and initiated changes in the composition of Archean seawater. Among our best records of biogeochemical cycles and seawater chemistry are organic carbon-rich black shales. Here we present a detailed multi-proxy study of 2.7 Ga black shales from the Abitibi Greenstone Belt, Canada. Abitibi shales demonstrate extreme enrichments in total organic carbon (up to 15 wt. %) and total sulfur (up to 6 wt. %) reflecting vigorous biogeochemical cycling in the basin, likely driven by cyanobacteria. The speciation of reactive Fe minerals indicates that pyrite formed in a sulfidic water column (euxinia) and that dissolved Fe was the limiting reactant. The deposition of more than 50 m of euxinic black shales suggests that the Fe-rich conditions reflected by Archean BIF deposition were not necessarily ubiquitous. Biologically significant trace metals fall into two categories. Metals that can be delivered to seawater in large quantities from hydrothermal sources (e.g., Cu and Zn) are enriched in the shales, reflecting their relative abundance in seawater. Conversely, metals that are primarily delivered to the ocean during oxidative weathering of the continents (e. g., Mo and V) are largely absent from the shales, reflecting depleted seawater inventories. Thus, trace metal supply at 2.7 Ga was still dominated by geological processes. Biological forcing of trace metal inventories, through oxidative weathering of the continents, was not initiated until 2.5 Ga, when Mo enrichments are first observed in the Mt. McRae Shale, Hamersley Basin. Multiple sulfur isotope analysis (32S, 33S, 34S) of disseminated pyrite displays large mass independent fractionations (Δ33S up to 6 %) reflecting a sulfur cycle dominated by atmospheric processes

  16. Age constraints on felsic intrusions, metamorphism and gold mineralisation in the Palaeoproterozoic Rio Itapicuru greenstone belt, NE Bahia State, Brazil

    Science.gov (United States)

    Mello, E.F.; Xavier, R.P.; McNaughton, N.J.; Hagemann, S.G.; Fletcher, I.; Snee, L.

    2006-01-01

    U-Pb sensitive high resolution ion microprobe mass spectrometer (SHRIMP) ages of zircon, monazite and xenotime crystals from felsic intrusive rocks from the Rio Itapicuru greenstone belt show two development stages between 2,152 and 2,130 Ma, and between 2,130 and 2,080 Ma. The older intrusions yielded ages of 2,152??6 Ma in monazite crystals and 2,155??9 Ma in zircon crystals derived from the Trilhado granodiorite, and ages of 2,130??7 Ma and 2,128??8 Ma in zircon crystals derived from the Teofila??ndia tonalite. The emplacement age of the syntectonic Ambro??sio dome as indicated by a 2,080??2-Ma xenotime age for a granite dyke probably marks the end of the felsic magmatism. This age shows good agreement with the Ar-Ar plateau age of 2,080??5 Ma obtained in hornblendes from an amphibolite and with a U-Pb SHRIMP age of 2,076??10 Ma in detrital zircon crystals from a quartzite, interpreted as the age of the peak of the metamorphism. The predominance of inherited zircons in the syntectonic Ambro??sio dome suggests that the basement of the supracrustal rocks was composed of Archaean continental crust with components of 2,937??16, 3,111??13 and 3,162??13 Ma. Ar-Ar plateau ages of 2,050??4 Ma and 2,054??2 Ma on hydrothermal muscovite samples from the Fazenda Brasileiro gold deposit are interpreted as minimum ages for gold mineralisation and close to the true age of gold deposition. The Ar-Ar data indicate that the mineralisation must have occurred less than 30 million years after the peak of the metamorphism, or episodically between 2,080 Ma and 2,050 Ma, during uplift and exhumation of the orogen. ?? Springer-Verlag 2006.

  17. Spinifex-textured komatiites in the south border of the Carajas ridge, Selva Greenstone belt, Carajás Province, Brazil

    Science.gov (United States)

    Siepierski, Lincoln; Ferreira Filho, Cesar Fonseca

    2016-03-01

    Spinifex-textured komatiites in the Selva greenstone belt are the first unequivocal examples of komatiites in the Transition Subdomain of the Carajás Mineral Province. Outcrops of spinifex-textured komatiites, located ∼1.5 km to the south of the Carajás ridge, were discovered during regional exploration for Ni-Cu-(PGE) sulfide deposits by VALE. They are associated with a 3.8 km long unit consisting of variable types of ultramafic rocks (talc schist, serpentinite and spinifex-textured komatiite). This ultramafic unit follows the steep dipping NW-SE trending Selva greenstone belt composed mainly by quartz-chlorite schists (interpreted as metasediments) and chlorite-actinolite schists (interpreted as metabasalts). Greenschist facies metamorphic parageneses characterize all rock types in the Selva greenstone belt. The komatiitic rocks in the Selva belt comprise a sequence of flows consisting of an upper spinifex-textured layer and a lower olivine cumulate layer. Although the spinifex and cumulus textures are well preserved in the field, the primary mineralogy of the komatiites has been completely replaced by greenschist facies metamorphic minerals. Platy olivine spinifex texture, consisting of an array of roughly parallel olivine plates, and random spinifex texture, consisting of randomly oriented olivine plates, are the most common primary volcanic textures in komatiites in the Selva greenstone belt. Platy and random spinifex texture is defined by former plates of olivine replaced by serpentine with minor actinolite, chlorite and magnetite, alternating with former matrix replaced by abundant actinolite and minor chlorite, talc, serpentine, and magnetite. The domains between olivine plates in both platy and random spinifex-textured rocks contain irregular arrays of fine-grained parallel crystals, representing primary fine-grained "quench" clinopyroxene crystals replaced by actinolite. Spinifex-textured komatiites have MgO contents bracket between 22.8 and 26.9 wt

  18. Brazil's premier gold province. Part I: The tectonic, magmatic, and structural setting of the Archean Rio das Velhas greenstone belt, Quadrilátero Ferrífero

    Science.gov (United States)

    Lobato, Lydia; Ribeiro-Rodrigues, Luiz; Zucchetti, Márcia; Noce, Carlos; Baltazar, Orivaldo; da Silva, Luiz; Pinto, Claiton

    2001-07-01

    Rocks of the Rio das Velhas Supergroup comprise one of the most significant Archean greenstone-belt successions in Brazil, in both their appreciable mineral productivity and extensive mineral potential. A large part of this greenstone belt is contained within the Quadrilátero Ferrífero (Iron Quadrangle) region, Minas Gerais state, southeastern Brazil, which occupies the southernmost portion of the São Francisco craton. The Nova Lima Group rocks, at the base of the Rio das Velhas greenstone belt, host important orogenic gold deposits. The group contains lithological associations from bottom to top as follows: (1) mafic-ultramafic volcanic, (2) volcanic-chemical, (3) clastic-chemical, (4) volcaniclastic, and (5) resedimented rocks. Rocks of the resedimented, volcanic-chemical, and mafic-ultramafic volcanic associations mainly host the most important gold deposits. An early compressional deformation occurs in the rocks of the Rio das Velhas greenstone belt and basement gneisses, with tangential thrusting from the north to the south or southwest. Structures generated during a second, compressional deformation, encompass NW-striking thrust faults and SW-vergent, tight to isoclinal folds, inferring a general southwest transport direction. In the central portion of the Quadrilátero Ferrífero, the Paciência lineament, which strikes northwest and dips to the northeast in the south, or strikes northeast and dips to the southeast in the north, is a thrust-related, oblique ramp fault that hosts important gold deposits. The convergence of these two trends in the Nova Lima region is accommodated by roughly E-W-striking transcurrent faults, which are the most favored sites for large gold concentrations. Intracratonic extension in Late Archean to early Paleoproterozoic times and NW-vergent, Trans-Amazonian compressional deformation post-date gold deposition. Late extension during the Paleoproterozoic led to basin formation and the prominent dome-and-keel architecture of the

  19. Structural, Petrographic and Geochemical Characteristics of Mafic Dikes Intrusive in Metasedimentary Rocks of the Crixás Greenstone Belt, Goiás

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    Hardy Jost

    2010-10-01

    Full Text Available Mafic dikes and stocks are a common feature in the Archean terrain of Goiás, Central Brazil, where they occur asswarms of 2.3 - 2.5 Ga within the granite-gneiss complexes (2.8 e 2.7 Ga, as well as intrusions related to the komatiite andbasalt flows of the greenstone belts lower stratigraphic units, but were unknown within the upper metasedimentary units.Detailed study of core sections from several drill-sites in the area of the Crixás greenstone belt gold deposits showed thatdike intrusion occurred after the main Paleoproterozoic deformation and metamorphism of the metasedimentary units,and literature data indicate that the magmatic zircons from the dikes yielded an age of 2,170 ± 17 Ma. Petrographic andgeochemical data show that they have the composition of epicratonic high-Ti diabases, which are similar to the largecontinental flood basalts of the Paraná Basin. The age of the intrusions may be correlated with the short time-interval of theRhyacian (2.20 to 2.17 Ga, during which successive localized episodes of mantle plume volcanism occurred on the Earth.

  20. The rheological behavior of fracture-filling cherts: example of Barite Valley dikes, Barberton Greenstone Belt, South Africa

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    M. Ledevin

    2014-05-01

    Full Text Available A 100 m-thick complex of near-vertical carbonaceous chert dikes marks the transition from the Mendon to Mapepe Formations (3260 Ma in the Barberton Greenstone Belt, South Africa. Fracturing was intense in this area, as shown by the profusion and width of the dikes (ca. 1 m on average and by the abundance of completely shattered rocks. The dike-and-sill organization of the fracture network and the upward narrowing of some of the large veins indicate that at least part of the fluid originated at depth and migrated upward in this hydrothermal plumbing system. Abundant angular fragments of silicified country rock are suspended and uniformly distributed within the larger dikes. Jigsaw-fit structures and confined bursting textures indicate that hydraulic fracturing was at the origin of the veins. The confinement of the dike system beneath an impact spherule bed suggests that the hydrothermal circulations were triggered by the impact and located at the external margin of a large crater. From the geometry of the dikes and the petrography of the cherts, we infer that the fluid that invaded the fractures was thixotropic. On one hand, the injection of black chert into extremely fine fractures is evidence for low viscosity at the time of injection; on the other hand, the lack of closure of larger veins and the suspension of large fragments in a chert matrix provide evidence of high viscosity soon thereafter. The inference is that the viscosity of the injected fluid increased from low to high as the fluid velocity decreased. Such rheological behavior is characteristic of media composed of solid and colloidal particles suspended in a liquid. The presence of abundant clay-sized, rounded particles of silica, carbonaceous matter and clay minerals, the high proportion of siliceous matrix and the capacity of colloidal silica to form cohesive 3-D networks through gelation, account for the viscosity increase and thixotropic behavior of the fluid that filled the

  1. REE geochemistry of 3.2 Ga BIF from the Mapepe Formation, Barberton Greenstone Belt, South Africa

    Science.gov (United States)

    Yahagi, T. R.; Yamaguchi, K. E.; Haraguchi, S.; Sano, R.; Teraji, S.; Kiyokawa, S.; Ikehara, M.; Ito, T.

    2012-12-01

    Banded iron formations (BIFs) are chemical sediments interbedded with Fe- and Si-rich layers, characteristically present in the early history of the Earth. A popular hypothesis for the formation of BIFs postulates that dissolved oxygen produced by photosynthesizers such as cyanobacteria oxidized dissolved ferrous Fe supplied by submarine hydrothermal activities. During precipitation of Fe-oxide minerals, phosphorus and rare earth elements (REEs) were most likely adsorbed on their surface. Therefore, chemical compositions of REEs that adsorbed onto Fe-oxide have useful information on the seawater chemistry at the time of deposition. Especially, information on the redox state of seawater and the extent of the contribution of hydrothermal activity during BIF deposition are expected to have been recorded. Occurrence of BIF has been traditionally tied to the chemical evolution of the atmosphere. Rise of atmospheric oxygen, or as known as GOE (Great Oxidation Event: e.g., Holland, 1994), has been widely believed to have occurred at around 2.4 Ga ago. Contrary, however, some studies have suggested that such oxygenation could have occurred much earlier (e.g., Hoashi et al., 2009). In this study, we used 3.2 Ga old BIF from the Mapepe Formation at the bottom of the Fig Tree Group of the Swaziland Supergroup in the northeastern part of the Barberton Greenstone Belt, South Africa. We aimed to constrain the marine environment, and by inference atmospheric environment, at the time of BIF deposition from REE geochemistry. Major elements and REE compositions of 37 samples were measured using XRF and ICP-MS, respectively. Samples with less than 1.0 wt% Al2O3 are considered to be "pure" BIFs with minimal amount of continental contamination, and are expected to have inherited marine REE signatures. Abundance of REE normalized by C1 chondrite for the analyzed samples commonly exhibits positive Eu anomaly and LREE

  2. Reworking Intensity—A Key Factor Leading to the Formation of Superlarge Gold Deposits in Greenstone Belts and Metamorphosed Microclastic Rocks in China

    Institute of Scientific and Technical Information of China (English)

    王秀璋; 陆德复; 等

    1999-01-01

    The greenstone belt and metamorphosed microclastic rock-type superlarge gold deposits in China are hosted in metamorphic rocks and later intrusive bodies.Sedimentation.regional metamorphism and mineralization contributed a lot to the formation of the deposits,so did remelting magmatic process to some deposits,but the deposits were finally formed by reworking processes.The key factor leading to the formation of superlarge gold deposits is the reworking intensity,which for superlarge gold deposits is reflected by the large-scale reworked source rocks and even ore materials of various sources,strongly oxidized ore-forming fluids with a long and repeated active history and stable geothermal heat current.The factor which decides the reworking intensity is the network consisting of structures of different classes.

  3. Trace-element fingerprints of chromite, magnetite and sulfides from the 3.1 Ga ultramafic-mafic rocks of the Nuggihalli greenstone belt, Western Dharwar craton (India)

    Science.gov (United States)

    Mukherjee, Ria; Mondal, Sisir K.; González-Jiménez, José M.; Griffin, William L.; Pearson, Norman J.; O'Reilly, Suzanne Y.

    2015-06-01

    The 3.1 Ga Nuggihalli greenstone belt in the Western Dharwar craton is comprised of chromitite-bearing sill-like ultramafic-mafic rocks that are surrounded by metavolcanic schists (compositionally komatiitic to komatiitic basalts) and a suite of tonalite-trondhjemite-granodiorite gneissic rocks. The sill-like plutonic unit consists of a succession of serpentinite (after dunite)-peridotite-pyroxenite and gabbro with bands of titaniferous magnetite ore. The chromitite ore-bodies (length ≈30-500 m; width ≈2-15 m) are hosted by the serpentinite-peridotite unit. Unaltered chromites from massive chromitites (>80 % modal chromite) of the Byrapur and Bhaktarhalli chromite mines in the greenstone belt are characterized by high Cr# (100Cr/(Cr + Al)) of 78-86 and moderate Mg# (100 Mg/(Mg + Fe2+)) of 45-55. In situ trace-element analysis (LA-ICPMS) of unaltered chromites indicates that the parental magma of the chromitite ore-bodies was a komatiite lacking nickel-sulfide mineralization. In the Ga/Fe3+# versus Ti/Fe3+# diagram, the Byrapur chromites plot in the field of suprasubduction zone (SSZ) chromites while those from Bhaktarhalli lie in the MOR field. The above results corroborate our previous results based on major-element characteristics of the chromites, where the calculated parental melt of the Byrapur chromites was komatiitic to komatiitic basalt, and the Bhaktarhalli chromite was derived from Archean high-Mg basalt. The major-element chromite data hinted at the possibility of a SSZ environment existing in the Archean. Altered and compositionally zoned chromite grains in our study show a decrease in Ga, V, Co, Zn, Mn and enrichments of Ni and Ti in the ferritchromit rims. Trace-element heterogeneity in the altered chromites is attributed to serpentinization. The trace-element patterns of magnetite from the massive magnetite bands in the greenstone belt are similar to those from magmatic Fe-Ti-V-rich magnetite bands in layered intrusions, and magnetites from

  4. Geochemical constraints on komatiite volcanism from Sargur Group Nagamangala greenstone belt, western Dharwar craton, southern India: Implications for Mesoarchean mantle evolution and continental growth

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    Tushipokla

    2013-05-01

    Full Text Available We present field, petrographic, major and trace element data for komatiites and komatiite basalts from Sargur Group Nagamangala greenstone belt, western Dharwar craton. Field evidences such as crude pillow structure indicate their eruption in a marine environment whilst spinifex texture reveals their komatiite nature. Petrographic data suggest that the primary mineralogy has been completely altered during post-magmatic processes associated with metamorphism corresponding to greenschist to lower amphibolite facies conditions. The studied komatiites contain serpentine, talc, tremolite, actinolite and chlorite whilst tremolite, actinolite with minor plagioclase in komatiitic basalts. Based on the published Sm-Nd whole rock isochron ages of adjoining Banasandra komatiites (northern extension of Nagamangala belt and further northwest in Nuggihalli belt and Kalyadi belt we speculate ca. 3.2–3.15 Ga for komatiite eruption in Nagamangala belt. Trace element characteristics particularly HFSE and REE patterns suggest that most of the primary geochemical characteristics are preserved with minor influence of post-magmatic alteration and/or contamination. About 1/3 of studied komatiites show Al-depletion whilst remaining komatiites and komatiite basalts are Al-undepleted. Several samples despite high MgO, (Gd/YbN ratios show low CaO/Al2O3 ratios. Such anomalous values could be related to removal of CaO from komatiites during fluid-driven hydrothermal alteration, thus lowering CaO/Al2O3 ratios. The elemental characteristics of Al-depleted komatiites such as higher (Gd/YbN (>1.0, CaO/Al2O3 (>1.0, Al2O3/TiO2 (18 together with higher HREE, Y, Zr suggest their derivation from shallower upper mantle without garnet involvement in residue. The observed chemical characteristics (CaO/Al2O3, Al2O3/TiO2, MgO, Ni, Cr, Nb, Zr, Y, Hf, and REE indicate derivation of the komatiite and komatiite basalt magmas from heterogeneous mantle (depleted to primitive mantle at

  5. Deep Metamorphic Rock Series of Bayan Wula-mountain Granite-greenstone Belt and Gold MineralizationMA Runze%巴彦乌拉山深变质岩系的花岗-绿岩带与金成矿

    Institute of Scientific and Technical Information of China (English)

    胡晰; 马润则; 陈志耕; 张腊梅; 陈娟; 刘颖倩

    2015-01-01

    A large area of Archean granite - greenstone belt exposed in Bayan wula-mountain, which bedrock outcrops good. Survey area′greenstone belt is existing as the green schist facies of tectonic schist. At present, domestic and foreign atta-ches great importance to the study of granite greenstone belt, The major reason is that research on it has mineral and geological sig-nificance. However, Gold directly affecting the financial securi-ty of the country as a precious metal, which is very important for the national economy stability. Granite - greenstone belt has a close relation with gold deposit. At present, China 's most im-portant gold producing type is greenstone type gold deposit.%巴彦乌拉山出露大面积的太古代花岗-绿岩带,基岩出露良好。本区的绿岩带是以变质程度为绿片相的构造片岩形式出现的。国内外对花岗绿岩带的研究非常重视,主要是因为其研究对矿产和地质都具有重大意义。然而金为直接影响国家金融安全的贵重金属,对于国家的经济稳定有极其重要的作用。其中花岗-绿岩带与金成矿有着密切关系。目前我国主要的产金类型为绿岩型金矿。

  6. Trace element geochemistry and petrogenesis of the granitoids and high-K andesite hosting gold mineralisation in the Archean Musoma-Mara Greenstone Belt, Tanzania

    Science.gov (United States)

    Kazimoto, Emmanuel Owden; Ikingura, Justinian R.

    2014-03-01

    Modern and ancient active continental margins are well known for their potential for hosting important gold deposits. The Neoarchean Musoma-Mara Greenstone Belt of the Tanzania Craton is also known for hosting several important gold deposits. Previous geochemical studies of the belt demonstrated that the rocks formed along Neoarchean convergent margins. The host rocks of the three important deposits in this belt had not yet been geochemically investigated. Therefore, we studied the host rocks of the Gokona, Nyabigena and Nyabirama gold deposits in the Neoarchean Musoma-Mara Greenstone Belt of the Tanzania Craton to determine the tectonic setting of their formation and constrain their petrogenesis. The host rocks of the Gokona and Nyabigena deposits are classified as high-K andesite, whereas the host rocks of the Nyabirama deposit are classified primarily as trondhjemite and granite and minor granodiorite (TGG). The high-K andesite and TGG were formed in an active continental margin similar to that of other Neoarchean volcanic rocks found in the Musoma-Mara Greenstone Belt. The host rocks contain low Ni and Cr concentrations and are characterised by negative Eu anomalies (Eu/Eu* = 0.67-0.72 and 0.17-0.6). The chondrite-normalised rare earth element (REE) patterns of the rocks display strong enrichment in light REEs over heavy REEs (high-K andesite (La/Yb)N = 21.7-35.6, and TGG (La/Yb)N = 2.4-94.4). Moreover, the primitive normalised diagrams show enrichment in large-ion lithophile elements (Ba, Rb, Th and K), negative Nb and Ta anomalies and depletion in heavy rare earth elements and high field-strength elements (Y and Ti). The high-K andesite has a Nb/Ta value close to that of depleted mantle (mean = 15.0), lower Zr/Sm values (19.4-30.6) and higher concentrations of REEs, large ion lithophile elements, Sr (607 ppm) and Y than in the TGG. The TGG has a low mean Nb/Ta value (13.2) and Sr concentration (283 ppm) and a lower amount of HREEs and higher values of Zr

  7. Environmental arsenic contamination and its health effects in a historic gold mining area of the Mangalur greenstone belt of Northeastern Karnataka, India.

    Science.gov (United States)

    Chakraborti, Dipankar; Rahman, Mohammad Mahmudur; Murrill, Matthew; Das, Reshmi; Siddayya; Patil, S G; Sarkar, Atanu; Dadapeer, H J; Yendigeri, Saeed; Ahmed, Rishad; Das, Kusal K

    2013-11-15

    This report summarizes recent findings of environmental arsenic (As) contamination and the consequent health effects in a community located near historic gold mining activities in the Mangalur greenstone belt of Karnataka, India. Arsenic contents in water, hair, nail, soil and food were measured by FI-HG-AAS. Elemental analyses of soils were determined by ICP-MS (inductively coupled plasma-mass spectrometry). Of 59 tube-well water samples, 79% had As above 10 μg L(-1) (maximum 303 μg L(-1)). Of 12 topsoil samples, six were found to contain As greater than 2000 mg kg(-1) possibly indicating the impact of mine tailings on the area. All hair and nail samples collected from 171 residents contained elevated As. Arsenical skin lesions were observed among 58.6% of a total 181 screened individuals. Histopathological analysis of puncture biopsies of suspected arsenical dermatological symptoms confirmed the diagnosis in three out of four patients. Based on the time-course of As-like symptoms reported by the community as well as the presence of overt arsenicosis, it is hypothesized that the primary route of exposure in the study area was via contaminated groundwater; however, the identified high As content in residential soil could also be a significant source of As exposure via ingestion. Additional studies are required to determine the extent as well as the relative contribution of geologic and anthropogenic factors in environmental As contamination in the region. This study report is to our knowledge one of the first to describe overt arsenicosis in this region of Karnataka, India as well as more broadly an area with underlying greenstone geology and historic mining activity. Copyright © 2012 Elsevier B.V. All rights reserved.

  8. Metallogeny of subduction zones

    Directory of Open Access Journals (Sweden)

    Sorokhtin N. O.

    2017-03-01

    Full Text Available The paper deals with the multistage mechanism of the Earth's crust enrichment in ore elements in underthrust zones. The processes of metamorphism and the formation of hydrothermal solutions at pulling of the watered oceanic lithospheric plate into the subduction zone have been described. Some physical and chemical transformation regularities of structural-material complexes in these areas and mechanisms of the formation of ore deposits have been discussed. Spatio-temporal patterns of the localization of a number of endogenetic and exogenetic deposits have been described using metallogeny of the Ural and the Verkhoyansk-Kolyma Fold Belts as an example. It has been shown that in nature there are several effective mechanisms of the enrichment of the crust in ore minerals. One of them is the process of pulling into subduction zone of metalliferous sediments and ferromanganese crusts as well as seabed nodules, their metamorphic transformation, partial melting and transition of ore components into magmatic melts and mineralized fluids. In the future this leads to the release of ore material by magmas and hydrothermal solutions into the folded formations of island-arc and Andean types and the formation of igneous, metasomatic and hydrothermal deposits. Another, yet no less powerful natural mechanism of a conveyor enrichment of the crust in ore elements is the process of destruction and sedimentation of mineral deposits formed in the folded areas as well as the formation of placers and their transfer to the marginal parts of the continent. Later, during the collision of active and passive margins of two lithospheric plates, such as the collision of the Kolyma Massif with the eastern part of the Siberian craton in the middle of the Mesozoic there was a thrusting of a younger lithospheric plate over a more ancient one. As a result, the sedimentary sequences of the passive margin of the Siberian plate were submerged and partially melted by the basic magmas

  9. Brazil's premier gold province. Part II: geology and genesis of gold deposits in the Archean Rio das Velhas greenstone belt, Quadrilátero Ferrífero

    Science.gov (United States)

    Lobato, Lydia; Ribeiro-Rodrigues, Luiz; Vieira, Frederico

    2001-07-01

    Orogenic, gold deposits are hosted by rocks of the Archean Rio das Velhas greenstone belt in the Quadrilátero Ferrífero region, Minas Gerais state, Brazil, one of the major gold provinces in the world. The gold deposits occur at the base of the mafic-ultramafic succession, with the most important orebodies controlled by E-W-striking, strike-slip faults. The main mineralization styles are (1) structurally controlled, sulfide replacement zones in banded iron formation (BIF); (2) disseminated sulfide minerals and gold in hydrothermally altered rocks along shear zones; and (3) auriferous quartz-carbonate-sulfide veins and veinlets in mafic, ultramafic, and felsic volcanic rocks, and also in clastic sedimentary rocks. The most common host rocks for ore are metamorphosed oxide- and carbonate-facies banded iron (± iron-rich metachert) formations (e.g., the Cuiabá, São Bento and Raposos deposits) and the lapa seca unit, which is a local term for intensely carbonatized rock (e.g., the giant Morro Velho mine with >450 t of contained gold). Metabasalts host most of the remaining gold deposits. Mineralogical characteristics and fluid inclusion studies suggest variations in the H2O/CO2 ratio of a low-salinity, near-neutral, reducing, sulfur-bearing, ore fluid. The presence of abundant CH4-rich inclusions is related to reduction of the original H2O-CO2 fluid via interaction with carbonaceous matter in the wallrocks. Oxygen fugacity was close to that of graphite saturation, with variations likely to have been influenced by reaction with the carbonaceous matter. Carbon-rich phyllites and schists, which commonly bound ore-bearing horizons, seem to have played both a physical and chemical role in localizing hydrothermal mineral deposition. Microtextural studies indicate that gold deposition was mainly related to desulfidation reactions, and was paragenetically coeval with precipitation of arsenic-rich iron sulfide minerals. Carbon isotope data are compatible with dissolution of

  10. Compositional Grading in an Impact-produced Spherule Bed, Barberton Greenstone Belt, South Africa: A Key to Condensation History of Rock Vapor Clouds

    Science.gov (United States)

    Krull, A. E.; Lowe, D. R.; Byerly, G. R.

    2003-01-01

    The chemical and physical processes by which spherules form during the condensation of impact-produced rock vapor clouds are poorly understood. Although efforts have been made to model the processes of spherule formation, there is presently a paucity of field data to constrain the resulting theoretical models. The present study examines the vertical compositional variability in a single early Archean spherule bed in the Barberton Greenstone Belt (BGB), South Africa, in order to better identify the process by which impact vapor clouds condense and spherules form and accumulate. The BGB spherule beds are suitable for this type of study because of their great thickness, often exceeding 25cm of pure spherules, due to the massive sizes of the impactors. Two main problems complicate analysis of vertical compositional variability of graded spherule beds: (1) differential settling of particles in both the vapor and water column due to density and size differences and (2) turbulence within the vapor cloud. The present study compares sections of spherule bed S3 from four different depositional environments in the Barberton Greenstone Belt: (1) The Sheba Mine section (SAF-381) was deposited under fairly low energy conditions in deep water, providing a nice fallout sequence, and also has abundant Ni-rich spinels; (2) Jay's Chert section (SAF-380) was deposited in subaerial to shallow-water conditions with extensive post-depositional reworking by currents. The spherules also have preserved spinels; (3) the Loop Road section (loc. SAF-295; samp. KSA-7) was moderately reworked and has only rare preservation of spinels; and (4) the shallow-water Barite Syncline section (loc. SAF-206; samp KSA-1) has few to no spinels preserved and is not reworked. Although all of the spherule beds have been altered by silica diagenesis and K-metasomatism, most of the compositional differences between these sections appear to reflect their diagenetic histories, possibly related to their differing

  11. High-resolution geology, petrology and age of a tectonically accreted section of Paleoarchean oceanic crust, Barberton greenstone belt, South Africa

    Science.gov (United States)

    Grosch, Eugene; Vidal, Olivier; McLoughlin, Nicola; Whitehouse, Martin

    2015-04-01

    The ca. 3.53 to 3.29 Ga Onverwacht Group of the Barberton greenstone belt (BGB), South Africa records a rare sequence of exceptionally well-preserved volcanic, intrusive and volcani-clastic Paleaoarchean rocks. Numerous conflicting models exist for the geologic evolution and stratigraphy of this early Archean greenstone belt, ranging from plume-type dynamics to modern-style plate tectonics. Although much work has focussed on the komatiites of the ca. 3.48 Ga Komati Formation since their discovery in 1969, far less petrological attention has been given to the younger oceanic rock sequences of the Kromberg type-section in the mid-Onverwacht Group. In this study, we present new field observations from a detailed re-mapping of the Kromberg type-section, and combine this with high-resolution lithological observations from continuous drill core of the Barberton Scientific Drilling Project [1]. The new mapping and field observations are compared to a recent preliminary study of the Kromberg type-section [2]. A U-Pb detrital provenance study was conducted on a reworked, volcani-clastic unit in the upper Kromberg type-section for the first time. This included U-Pb age determination of 110 detrital zircons by secondary ion microprobe analyses (SIMS), providing constraints on maximum depositional age, provenance of the ocean-floor detritus, and timing for the onset of Kromberg ocean basin formation. These new zircon age data are compared to a previous U-Pb detrital zircon study conducted on the structurally underlying sediments of the ca. 3.43 Ga Noisy formation [3]. A multi-pronged petrological approach has been applied to various rock units across the Kromberg, including thermodynamic modelling techniques applied to metabasalts and metapyroxenites for PT-estimates, bulk- and in-situ isotope geochemistry providing constraints on protolith geochemistry and metamorphic history. Consequently, it is shown that this previously poorly studied Kromberg oceanic rock sequence of the

  12. Paleoproterozoic Greenstone-Granite Belts in Northern Brazil and the Former Guyana Shield - West African Craton Province

    Directory of Open Access Journals (Sweden)

    Ian McReath

    2006-03-01

    Full Text Available The mainly meta-volcano-sedimentary Vila Nova Group and associated granites constitute separate belts, which formpart of a large paleoproterozoic (mainly rhyacian province in the Guyana Shield of which northern Brazil forms a part, andthe West African Craton. In Brazil the southwestern Serra do Ipitinga and Serra Tumucumaque-Serra do Navio belts have noobvious geometrical extensions in the Guyanas or Venezuela, and may represent deposits formed at penecontemporaneouspassive continental margins and ocean floor spreading centres. To the Northeast the Serra Lombarda-Tartarugalzinho andOiapoque belts are continuations of Guianese belts. In the former the igneous rocks have geochemical characteristics ofsuprasubduction environments. Belts in the Guyana Shield and West African Craton have many similar features. Themegaprovince evolved in a number of stages, which may have started at about 2.3 Ga, and continued with diminished activityafter 2.11 Ga. Both major juvenile additions and (possibly minor reworking of earlier crust contributed to the growth of theprovince. The major transcurrent deformation, responsible for the present structure of the belts, probably occurred duringthe later stages of evolution of the province, but metamorphism and deformation are registered even in the oldest rocks.

  13. Archean deep-water depositional system: interbedded and banded iron formation and clastic turbidites in the Barberton Greenstone Belt, South Africa

    Science.gov (United States)

    Zentner, Danielle; Lowe, Donald

    2013-04-01

    The 3.23 billion year old sediments in the Barberton greenstone belt, South Africa include some of the world's oldest known deep-water deposits. Unique to this locality are turbidites interbedded with banded iron formation (BIF) and banded ferruginous chert (BFC). This unusual association may provide clues for reconstructing Archean deep-water depositional settings. For our study we examined freshly drilled core in addition to measuring ~500 m of outcrop exposures along road cuts. The stacking pattern follows an overall BIF to BFC to amalgamated turbidite succession, although isolated turbidites do occur throughout the sequence. The turbidites are predominately massive, and capped with thin, normally graded tops that include mud rip-ups, chert plates, and ripples. The lack of internal stratification and the amalgamated character suggests emplacement by surging high-density turbidity currents. Large scours and channels are absent and bedding is tabular: the flows were collapsing with little turbulence reaching the bed. In contrast, field evidence indicates the BIF and BFC most likely precipitated directly out of the water column. Preliminary interpretations indicate the deposits may be related to a pro-deltaic setting. (1) Deltaic systems can generate long-lived, high volume turbidity currents. (2) The contacts between the BIF, BFC, and turbidite successions are gradual and inter-fingered, possibly representing lateral facies relationships similar to modern pro-delta environments. (3) Putative fan delta facies, including amalgamated sandstone and conglomerate, exist stratigraphically updip of the basinal sediments.

  14. Geochemistry and petrogenesis of the K-rich 'Bongo-type' granitoids in the Paleoproterozoic Bole-Nangodi greenstone belt of Ghana

    Science.gov (United States)

    Abitty, Emmanuel K.; Dampare, Samuel B.; Nude, Prosper M.; Asiedu, Daniel K.

    2016-10-01

    The 'Bongo-type' granitoids intrude the northern portion (where it cross cuts the Tarkwaian), central and south-central portions of the Bole-Nangodi greenstone belt in Ghana. The non-foliated, porphyritic granitoids are characterised by microcline (5-18 mm), often set in a medium to fine grained matrix of quartz and plagioclase, contains granular quartz and show incipient development of mymerkites under thin section. The major mafic phases are a brownish-green variety of hornblende ± biotite, with sphene, epidote and apatite occurring as accessory minerals. The pink looking 'Bongo-type' granitoids are classified as granites with subordinate granodiorites and quartz monzonites. Whole-rock geochemical analyses show that the granitoids are magnesian and metaluminous to weakly peraluminous. On the basis of their Th-Co-K2O and SiO2 contents, the granitoids classified as high-K calc-alkaline and shoshonite series rocks. They show enriched LILE trends, decoupled LILE-HFSE patterns, negative Ta-Nb anomaly, pronounced negative Ti anomaly and variable positive and negative Sr anomalies. The K-rich granitoids from the middle and south-central portions of the Bole-Nangodi belt show the lowest concentrations of LILE and some HFSE with the most prominent negative Ti and Si anomalies. The 'Bongo-type' granitoids show I-type characteristics. Based on Ba-U-Th concentrations, they are interpreted to have had some interaction with crustal materials or some influence of subducted sediments. The granitoids unequivocally show subduction-related signatures and mimic high silica adakites (HSA). They show evidence of being emplaced in a volcanic arc geotectonic environment. Their geochemical similarities to A-type granitoids, however, suggest an arc-back-arc tectonic setting.

  15. Potential of thermal emissivity for mapping of greenstone rocks and associated granitoids of Hutti Maski Schist belt, Karnataka

    OpenAIRE

    Guha, A.; K.Vinod Kumar

    2014-01-01

    In the present study, different temperature-emissivity separation algorithms were used to derive emissivity images based on processing of ASTER( Advanced spaceborne thermal emission and reflection radiometer) thermal bands. These emissivity images have been compared with each other in terms of geological information for mapping of major rock types in Hutti Maski schist Belt and its associated granitoids. Thermal emissivity images are analyzed conjugately with thermal radiance image, ...

  16. Microstructural analysis of a subhorizontal gold-quartz vein deposit at Donalda, Abitibi greenstone belt, Canada: Implications for hydrodynamic regime and fluid-structural relationship

    Directory of Open Access Journals (Sweden)

    Guoxiang Chi

    2011-10-01

    Full Text Available The Donalda gold deposit in the southern part of the Archean Abitibi greenstone belt consists mainly of a subhorizontal gold-quartz vein perpendicular to subvertical shear zones. The 0.3–0.5 m thick vein is characterized by vein-parallel banding structures indicating multiple episodes of fracture opening and mineral precipitation. Measurement of the c-axis of primary growth quartz indicates that quartz preferentially grew perpendicular to the fracture, suggesting open space filling and/or extensional nature of the fracture. Measurement of the orientations of microfractures, veinlets and fluid–inclusion planes (FIPs crosscutting primary growth quartz indicates that the vein minerals were subject to a vertical maximum principal stress (σ1, which is inconsistent with the subhorizontal σ1 inferred from the regional stress field with N–S shortening. This apparent discrepancy is explained by invoking episodic fluid pressure fluctuation between supralithostatic and hydrostatic regimes accompanied by episodic opening and closing of the subhorizontal fracture. When fluid pressure was higher than the lithostatic value, the fracture was opened and primary growth minerals were precipitated, whereas when fluid pressure decreased toward the hydrostatic value, the hanging wall of the fracture collapsed, causing collision of protruding primary growth minerals from both sides of the fracture and resulting in formation of vein-parallel deformation bands. The columns where the two facing sides of the fracture collided were subject to higher-than-lithostatic stress due to the bridging effect and reduced support surface area, explaining the development of vertical σ1. This hypothesis is consistent the fault-valve model, and explains the flipping of σ1 without having to change the regional stress field.

  17. Geochemistry and petrogenesis of the late Archaean high-K granites in the southern Musoma-Mara Greenstone Belt: Their influence in evolution of Archaean Tanzania Craton

    Science.gov (United States)

    Mshiu, Elisante Elisaimon; Maboko, Makenya A. H.

    2012-05-01

    Musoma-Mara Greenstone Belt (MMGB) is abundantly occupied by the post-orogenic high-K granites which also they mark the end of magmatism in the area. The granites are characterized by high SiO2 and Al2O3 contents that average 74.42% and 13.08% by weight respectively. They have low Na2O content (mean = 3.36 wt.%) and high K2O contents (mean = 4.95 wt.%) which resulted to relatively high K2O/Na2O ratios (mean = 1.50). They also characterized by low Mg# (mean = 33) as well as low contents of transition elements such as Cr and Ni which are below detection limit (<20 ppm). Negative anomalies in Eu (Eu/Eu*, mean = 0.56), Nd, Ta and Ti elements as shown in the chondrite and primitive mantle normalized diagrams indicate MMGB high-K granites originated from a subduction related environments. These high-K granites also characterized by relative enrichment of the LREE compared to HREE as revealed by their high (La/Yb)CN ratio ranging from 8.71 to 50.93 (mean = 26.32). They have relatively flat HREE pattern with (Tb/Yb)CN ratio varying between 0.81 and 2.12 (mean = 1.55). Their linear trend in the variation diagrams of both major and trace elements indicate magmatic differentiation was also an important process during their formation. Conclusively, the geochemical characteristics as well as experimental evidences suggests MMGB high-K granites were formed from partial melting of pre-existing TTG rocks, under low pressure at 15 km depth or less and temperature around 950 °C in which plagioclase minerals were the stable phases in the melt.

  18. Gold Deposit Metallogenic Condition and Type Analysis in Manica Greenstone Belt, Mozambique%莫桑比克马尼卡绿岩带金矿成矿条件和类型分析

    Institute of Scientific and Technical Information of China (English)

    邓宇涛; 李胜利; 王松

    2015-01-01

    The gold producing area in Mozambique is situated in the Manica greenstone belt. It is a part of Manica-Mutare-Odzi (MMO) greenstone belt, from Odzi in eastern Zimbabwe through Mutare extend to Manica area in western Mozambique and make the ar-ea the most important gold deposit metallogenic belt in the country. The gold deposit is mainly enriched in a shear zone, banded iron-bearing formation of Archean mafic and ultramafic volcanic rocks or in faulted contact zone between supracrustal rocks and peripheral granite.%莫桑比克黄金产区位于马尼卡绿岩带,该绿岩带是马尼卡(Manica)-穆塔雷(Mutare)-奥德兹(Odzi)绿岩带的一部分,从津巴布韦东部奥德兹经过穆塔雷一直延伸到莫桑比克西部马尼卡地区,使马尼卡地区成为莫桑比克最重要的金矿成矿带.金矿主要富集在太古代镁铁质和超镁铁质火山岩中的剪切带、条带状含铁建造或在表壳岩与周边花岗岩之间的断裂接触带中.

  19. Early Cambrian Post-collisional volcanosedimentary Rey Bouba greenstone belt in northern Cameroun: LA-MC-ICP-MS U-Pb geochronology and implications for the geodynamic evolution of the Central African Fold Belt (CAFB).

    Science.gov (United States)

    Bouyo, Merlain

    2014-05-01

    The Rey Bouba Greenstone Belt (RBGB) is a greenschist volcanosedimentary basin representing the youngest accretion event that characterized the geodynamic evolution of the CAFB of Northern Cameroon. LA-MC-ICP-MS U-Pb detrital zircon data indicate that both older PP to MP and younger NP to Early Cambrian sources from ca 2000 to ca 540 Ma, with main provenance being zircon grains from Cryogenian igneous rocks (between ca 850 and ca 650 Ma) were involved in the formation of the RBGB basin. Considering the age of metamorphism inferred from high pressure granulites at ca 600 Ma within the CAFB of northern Cameroon as the most direct evidence for the timing of continental collision, we conclude that the deformation associated with migmatites and post-collisional granites which fed the Rey Bouba basin mostly with NP zircon lasts until post 540 Ma, in correlation with the final amalgamation of the Gondwana Supercontinent during Latest Neoproterozoic-Earliest Cambrian. Therefore, the RBGB may represent the youngest post-collisional metavolcanosedimentary basin within the CAFB.

  20. Geochemical characteristics of aluminum depleted and undepleted komatiites and HREE-enriched low-Ti tholeiites, western Abitibi greenstone belt: A heterogeneous mantle plume-convergent margin environment

    Science.gov (United States)

    Fan, J.; Kerrich, R.

    1997-11-01

    A compositionally diverse suite of komatiites, komatiitic basalts, and basalts coexist in the Tisdale volcanic assemblage of the late-Archean (˜2.7 Ga) Abitibi greenstone belt. The komatiites are characterized by a spectrum of REE patterns, from low total REE contents (9 ppm) and pronounced convex-up patterns to greater total REE (18 ppm) and approximately flat-distributions. Thorium and niobium are codepleted with LREE. Komatiites with the most convex-up patterns have low Al 2O 3 (4.7 wt%) contents and Al 2O 3/TiO 2(12) ratios; they are interpreted to be the Al-depleted variety of komatiite derived from a depleted mantle source. Those komatiites and komatiitic basalts with flatter REE patterns are characterized by greater Al 2O 3 (7.0 wt%) and near chondritic Al 2O 3/TiO 2 (20) ratios; they are interpreted to be Al-undepleted komatiites generated from trace element undepleted mantle. For the komatiites and komatiitic basalts collectively, Gd/Ybn ratios are negatively correlated with La/Smn, but positively with MgO and Ni. The spectrum of patterns is interpreted as mixing between Al, HREE, Y-depleted, and Sc-depleted komatiites and Al-undepleted komatiites in a heterogeneous mantle plume. Auminum-depleted komatiites are characterized by negative Zr and Hf anomalies, consistent with majorite garnet-liquid D's for HFSE and REEs, signifying melt segregation at depths of >400 km. Tisdale Al-undepleted komatiites and komatiitic basalts have small negative to zero Zr(Hf)/MREE fractionation, signifying melt segregation in or above the garnet stability field. Collectively, the komatiites have correlations of Zr/Zr∗ and Hf/Hf ∗ with Gd/Ybn, and hence the Zr(Hf)/MREE fractionations are unlikely to have stemmed from alteration or crustal contamination. Two types of basalts are present. Type I basalts are Mg-tholeiites with near flat REE and primitive mantle normalized patterns, compositionally similar to abundant Mg-tholeiites associated with both Al-undepleted and Al

  1. Sulfur isotope mass-independent fractionation in impact deposits of the 3.2 billion-year-old Mapepe Formation, Barberton Greenstone Belt, South Africa

    Science.gov (United States)

    van Zuilen, M. A.; Philippot, P.; Whitehouse, M. J.; Lepland, A.

    2014-10-01

    Theoretical and experimental studies have shown that atmospheric SO2 isotopologue self-shielding effects in the 190-220 nm region of the solar spectrum are the likely cause for mass independent fractionation of sulfur isotopes (S-MIF). The main products of this photochemical reaction - SO3 and S0 - typically define a compositional array of ca. Δ33S/δ34S = 0.06-0.14. This is at odds with the generally observed trend in Archean sulfides, which broadly defines an array of ca. Δ33S/δ34S = 0.9. Various explanations have been proposed, including a diminution of δ34S caused by chemical and biogenic mass-dependent fractionation of sulfur isotopes (S-MDF), mixing with photolytic products produced during felsic volcanic events, or partial blocking of the low-wavelength part of the spectrum due to the presence of reduced atmospheric gases or an organic haze. Early in Earth history large meteorite impacts would have ejected dust and gas clouds into the atmosphere that shielded solar radiation and affected global climate. It is thus likely that at certain time intervals of high meteorite flux the atmosphere was significantly perturbed, having an effect on atmospheric photochemistry and possibly leaving anomalous sulfur isotopic signatures in the rock record. Here we describe the sulfur isotopic signatures in sulfides of spherule beds S2, S3 and S4 of the Barberton Greenstone Belt, South Africa. In particular, in spherule bed S3 - and to a lesser extent S4 - a trend of ca. Δ33S/δ34S = 0.23 is observed that closely follows the expected trend for SO2-photolysis in the 190-220 nm spectral range. This suggests that an impact dust cloud (deposited as spherule beds), which sampled the higher region of the atmosphere, specifically incorporated products of SO2 photolysis in the 190-220 nm range, and blocked photochemical reactions at higher wavelengths (250-330 nm band). By implication, the generally observed Archean trend appears to be the result of mixing of different MIF

  2. Oceanic plateau model for continental crustal growth in the Archaean: A case study from the Kostomuksha greenstone belt, NW Baltic Shield

    Science.gov (United States)

    Samsonov, A. V.; Shchipansky, A. A.; Jochum, K. P.; Mezger, K.; Hofmann, A. W.; Puchtel, I. S.

    1998-02-01

    Field studies combined with chemical and isotope data indicate that the Kostomuksha greenstone belt in the NW Baltic Shield consists of two lithotectonic terranes, one mafic igneous and the other sedimentary, separated by a major shear zone. The former contains submarine komatiite-basalt lavas and volcaniclastic lithologies, and the latter is composed of shelf-type rocks and BIF. Komatiitic and basaltic samples yield Sm-Nd and Pb-Pb isochron ages of 2843+/-39 and 2813+/-78 Ma, respectively. Their trace-element compositions resemble those of recent Pacific oceanic flood basalts with primitive-mantle normalized Nb/Th of 1.5-2.1 and Nb/La of 1.0-1.5. This is in sharp contrast with island arc and most continental magmas, which are characterized by Nb/(Th,La)N≪1. Calculated initial Nd-isotope compositions (ɛNd(T)=+2.8 to +3.4) plot close to an evolution line previously inferred for major orogens (``MOMO''), which is also consistent with the compositions of recent oceanic plateaux. The high liquidus temperatures of the komatiite magmas (1550°C) and their Al-depleted nature require an unusually hot (1770°C) mantle source for the lavas (>200°C hotter than the ambient mantle at 2.8 Ga), and are consistent with their formation in a deep mantle plume in equilibrium with residual garnet. This plume had the thermal potential to produce oceanic crust with an average thickness of ~30 km underlain by a permanently buoyant refractory lithospheric mantle keel. Nb/U ratios in the komatiites and basalts calculated on the basis of Th-U-Pb relationships range from 35 to 47 and are thus similar to those observed in modern MORB and OIB. This implies that some magma source regions of the Kostomuksha lavas have undergone a degree of continental material extraction comparable with those found in the modern mantle. The mafic terrane is interpreted as a remnant of the upper crustal part of an Archaean oceanic plateau. When the newly formed plateau reached the active continental margin

  3. Tracing sources of crustal contamination using multiple S and Fe isotopes in the Hart komatiite-associated Ni-Cu-PGE sulfide deposit, Abitibi greenstone belt, Ontario, Canada

    Science.gov (United States)

    Hiebert, R. S.; Bekker, A.; Houlé, M. G.; Wing, B. A.; Rouxel, O. J.

    2016-10-01

    Assimilation by mafic to ultramafic magmas of sulfur-bearing country rocks is considered an important contributing factor to reach sulfide saturation and form magmatic Ni-Cu-platinum group element (PGE) sulfide deposits. Sulfur-bearing sedimentary rocks in the Archean are generally characterized by mass-independent fractionation of sulfur isotopes that is a result of atmospheric photochemical reactions, which produces isotopically distinct pools of sulfur. Likewise, low-temperature processing of iron, through biological and abiotic redox cycling, produces a range of Fe isotope values in Archean sedimentary rocks that is distinct from the range of the mantle and magmatic Fe isotope values. Both of these signals can be used to identify potential country rock assimilants and their contribution to magmatic sulfide deposits. We use multiple S and Fe isotopes to characterize the composition of the potential iron and sulfur sources for the sulfide liquids that formed the Hart deposit in the Shaw Dome area within the Abitibi greenstone belt in Ontario (Canada). The Hart deposit is composed of two zones with komatiite-associated Ni-Cu-PGE mineralization; the main zone consists of a massive sulfide deposit at the base of the basal flow in the komatiite sequence, whereas the eastern extension consists of a semi-massive sulfide zone located 12 to 25 m above the base of the second flow in the komatiite sequence. Low δ56Fe values and non-zero δ34S and Δ33S values of the komatiitic rocks and associated mineralization at the Hart deposit is best explained by mixing and isotope exchange with crustal materials, such as exhalite and graphitic argillite, rather than intrinsic fractionation within the komatiite. This approach allows tracing the extent of crustal contamination away from the deposit and the degree of mixing between the sulfide and komatiite melts. The exhalite and graphitic argillite were the dominant contaminants for the main zone of mineralization and the eastern

  4. The geology of the Morro Velho gold deposit in the Archean Rio das Velhas greenstone belt, Quadrilátero Ferrífero, Brazil

    Science.gov (United States)

    Vial, Diogenes Scipioni; DeWitt, Ed; Lobato, Lydia Maria; Thorman, Charles H.

    2007-01-01

    The Morro Velho gold deposit, Quadrilátero Ferrífero region, Minas Gerais, Brazil, is hosted by rocks at the base of the Archean Rio das Velhas greenstone belt. The deposit occurs within a thick carbonaceous phyllite package, containing intercalations of felsic and intermediate volcaniclastic rocks and dolomites. Considering the temporal and spatial association of the deposit with the Rio das Velhas orogeny, and location in close proximity to a major NNW-trending fault zone, it can be classified as an orogenic gold deposit. Hydrothermal activity was characterized by intense enrichment in alteration zones of carbonates, sulfides, chlorite, white mica±biotite, albite and quartz, as described in other Archean lode-type gold ores. Two types of ore occur in the deposit: dark gray quartz veins and sulfide-rich gold orebodies. The sulfide-rich orebodies range from disseminated concentrations of sulfide minerals to massive sulfide bodies. The sulfide assemblage comprises (by volume), on average, 74% pyrrhotite, 17% arsenopyrite, 8% pyrite and 1% chalcopyrite. The orebodies have a long axis parallel to the local stretching lineation, with continuity down the plunge of fold axis for at least 4.8 km. The group of rocks hosting the Morro Velho gold mineralization is locally referred to as lapa seca. These were isoclinally folded and metamorphosed prior to gold mineralization. The lapa seca and the orebodies it hosts are distributed in five main tight folds related to F1 (the best examples are the X, Main and South orebodies, in level 25), which are disrupted by NE- to E-striking shear zones. Textural features indicate that the sulfide mineralization postdated regional peak metamorphism, and that the massive sulfide ore has subsequently been neither metamorphosed nor deformed. Lead isotope ratios indicate a model age of 2.82 ± 0.05 Ga for both sulfide and gold mineralization. The lapa seca are interpreted as the results of a pre-gold alteration process and may be

  5. Carbonaceous matter and putative microfossils of the mid-Archean Kromberg type-section re-visited, Barberton Greenstone Belt, South Africa

    Science.gov (United States)

    McLoughlin, Nicola; Grosch, Eugene

    2014-05-01

    Silicified seafloor sediments of the Kromberg Formation from the Onverwacht Group of the Barberton greenstone belt (BGB), South Africa, have been argued to contain some of the world's oldest preserved carbonaceous microfossils. Previous studies of these cherts have reported filamentous, spheroidal and ellipsoidal microfossils in thin-section (Walsh 1992); and bacteriomorph like structures in HF-etched samples (Westall et al. 2001). These microtextural studies however, lack supporting in-situ geochemical data, and are hampered to some degree by re-mobilisation of the carbonaceous matter (Van Zuilen et al. 2007). In light of these concerns, and ongoing debates surrounding carbonaceous remains in other Archean cherts (e.g., W Australia), further in-situ data from the Kromberg is required to positively identify carbonaceous matter of biogenic origin. New data will also help to address outstanding questions regarding the relative contribution of benthic versus planktonic microorganisms, and the putative microbial metabolisms involved. This study focuses on surface samples and drill core from the Barberton Scientific Drilling Programme, (BSDP, Grosch et al. 2009) from the southeastern limb of the Onverwacht anticline of the BGB. We sampled the Footbridge chert and a second chert horizon in drill core KD1 of the BSDP in the upper Kromberg Fm; and surface outcrops of two black cherts from the lower Kromberg Fm. Sedimentological logging reveals horizons rich in volcaniclastics with interbedded finely laminated grey-black chert, also intrusive black cherts, and sulphide rich horizons. The TOC of the sampled cherts is 1.24 to 5.40 wt%. Preliminary bulk carbon isotope values range from δ13C -21.1 to -35.3o values that are consistent with organic matter produced by anoxygenic photosynthesis. Microfabrics preserved in the Kromberg cherts include, primary wispy-laminated carbonaceous films suggesting compaction of early carbonaceous laminae. Also large composite carbonaceous

  6. Metamorphic fluid flow in the northeastern part of the 3.8-3.7 Ga Isua Greenstone Belt (SW Greenland): A re-evalution of fluid inclusion evidence for early Archean seafloor-hydrothermal systems

    DEFF Research Database (Denmark)

    Heijlen, Wouter; Appel, P. W. U.; Frezzotti, M. L.;

    2006-01-01

    segregations showed that they were affected by variable recrystallization which controlled their fluid inclusion content. The oldest unaltered fluid inclusions found are present in vein crystals that survived dynamic and static recrystallization. These crystals contain a cogenetic, immiscible assemblage of CO2......-NaCl (0.2-3.7 eq. wt% NaCl.) These successive fluid inclusion assemblages record a retrograde P-T evolution close to a geothermal gradient of similar to 30 degrees C/km, but also indicate fluid pressure variations and the introduction of highly reducing fluids at similar to 200-300 degrees C and 0......Fluid inclusions in quartz globules and quartz veins of a 3.8-3.7 Ga old, well-preserved pillow lava breccia in the northeastern Isua Greenstone Belt (IGB) were studied using microthermometry, Raman spectrometry and SEM Cathodoluminescence Imaging. Petrographic study of the different quartz...

  7. New constraints on the Paleoarchean meteorite bombardment of the Earth - Geochemistry and Re-Os isotope signatures of spherule layers in the BARB5 ICDP drill core from the Barberton Greenstone Belt, South Africa

    Science.gov (United States)

    Schulz, Toni; Koeberl, Christian; Luguet, Ambre; van Acken, David; Mohr-Westheide, Tanja; Ozdemir, Seda; Reimold, Wolf Uwe

    2017-08-01

    Archean spherule layers, resulting from impacts by large extraterrestrial objects, to date represent the only remnants of the early meteorite, asteroid, and comet bombardment of the Earth. Only few Archean impact debris layers have been documented, all of them embedded in the 3.23-3.47 billion year old successions of the Barberton Greenstone Belt (BGB) in South Africa and the Pilbara Craton in Western Australia. Some of them might be correlated with each other. Given the scarcity of Archean spherule deposits, four spherule layer intersections from the recently recovered BARB5 drill core from the central Barberton Greenstone Belt, analyzed in this study, provide an opportunity to gain new insight into the early terrestrial impact bombardment. Despite being hydrothermally overprinted, siderophile element abundance signatures of spherule-rich samples from the BARB5 drill core, at least in part, retained a meteoritic fingerprint. The impact hypothesis for the generation of the BARB5 spherule layers is supported by correlations between the abundances of moderately (Cr, Co, Ni) and highly siderophile (Re, Os, Ir, Pt, Ru and Pd) elements, whose peak concentrations and interelement ratios are within the range of those for chondrites. Rhenium-Osmium isotope evidence further support the impact hypothesis. Collectively, this study provides evidence for extraterrestrial admixtures ranging between ∼40 and up to 100% to three of the four analyzed BARB5 spherule layers, and a scenario for their genesis involving (i) impact of a chondritic bolide into a sedimentary target, (ii) varying admixtures of meteoritic components to target materials, (iii) spherule formation via condensation in an impact vapor plume, (iv) transportation of the spherules and sedimentation under submarine conditions, followed by (v) moderate post-impact remobilization of transition metals and highly siderophile elements.

  8. Spherule Beds 3.47-3.24 Billion Years Old in the Barberton Greenstone Belt, South Africa: A Record of Large Meteorite Impacts and Their Influence on Early Crustal and Biological Evolution

    Science.gov (United States)

    Lowe, Donald R.; Byerly, Gary R.; Kyte, Frank T.; Shukolyukov, Alexander; Asaro, Frank; Krull, Alexander

    2003-01-01

    Four layers, S1-S4, containing sand-sized spherical particles formed as a result of large meteorite impacts, occur in 3.47-3.24 Ga rocks of the Barberton Greenstone Belt, South Africa. Ir levels in S3 and S4 locally equal or exceed chondritic values but in other sections are at or only slightly above background. Most spherules are inferred to have formed by condensation of impact-produced rock vapor clouds, although some may represent ballistically ejected liquid droplets. Extreme Ir abundances and heterogeneity may reflect element fractionation during spherule formation, hydraulic fractionation during deposition, and/or diagenetic and metasomatic processes. Deposition of S1, S2, and S3 was widely influenced by waves and/or currents interpreted to represent impact-generated tsunamis, and S1 and S2 show multiple graded layers indicating the passage of two or more wave trains. These tsunamis may have promoted mixing within a globally stratified ocean, enriching surface waters in nutrients for biological communities. S2 and S3 mark the transition from the 300-million-year-long Onverwacht stage of predominantly basaltic and komatiitic volcanism to the late orogenic stage of greenstone belt evolution, suggesting that regional and possibly global tectonic reorganization resulted from these large impacts. These beds provide the oldest known direct record of terrestrial impacts and an opportunity to explore their influence on early life, crust, ocean, and atmosphere. The apparent presence of impact clusters at 3.26-3.24 Ga and approx. 2.65-2.5 Ga suggests either spikes in impact rates during the Archean or that the entire Archean was characterized by terrestrial impact rates above those currently estimated from the lunar cratering record.

  9. Spherule Beds 3.47-3.24 Billion Years Old in the Barberton Greenstone Belt, South Africa: A Record of Large Meteorite Impacts and Their Influence on Early Crustal and Biological Evolution

    Science.gov (United States)

    Lowe, Donald R.; Byerly, Gary R.; Kyte, Frank T.; Shukolyukov, Alexander; Asaro, Frank; Krull, Alexander

    2003-01-01

    Four layers, S1-S4, containing sand-sized spherical particles formed as a result of large meteorite impacts, occur in 3.47-3.24 Ga rocks of the Barberton Greenstone Belt, South Africa. Ir levels in S3 and S4 locally equal or exceed chondritic values but in other sections are at or only slightly above background. Most spherules are inferred to have formed by condensation of impact-produced rock vapor clouds, although some may represent ballistically ejected liquid droplets. Extreme Ir abundances and heterogeneity may reflect element fractionation during spherule formation, hydraulic fractionation during deposition, and/or diagenetic and metasomatic processes. Deposition of S1, S2, and S3 was widely influenced by waves and/or currents interpreted to represent impact-generated tsunamis, and S1 and S2 show multiple graded layers indicating the passage of two or more wave trains. These tsunamis may have promoted mixing within a globally stratified ocean, enriching surface waters in nutrients for biological communities. S2 and S3 mark the transition from the 300-million-year-long Onverwacht stage of predominantly basaltic and komatiitic volcanism to the late orogenic stage of greenstone belt evolution, suggesting that regional and possibly global tectonic reorganization resulted from these large impacts. These beds provide the oldest known direct record of terrestrial impacts and an opportunity to explore their influence on early life, crust, ocean, and atmosphere. The apparent presence of impact clusters at 3.26-3.24 Ga and approx. 2.65-2.5 Ga suggests either spikes in impact rates during the Archean or that the entire Archean was characterized by terrestrial impact rates above those currently estimated from the lunar cratering record.

  10. Rb–Sr and Sm–Nd isotope systematics and geochemical studies on metavolcanic rocks from Peddavura greenstone belt: Evidence for presence of Mesoarchean continental crust in easternmost part of Dharwar Craton, India

    Indian Academy of Sciences (India)

    M Rajamanickam; S Balakrishnan; R Bhutani

    2014-07-01

    Linear, north–south trending Peddavura greenstone belt occurs in easternmost part of the Dharwar Craton. It consists of pillowed basalts, basaltic andesites, andesites (BBA) and rhyolites interlayered with ferruginous chert that were formed under submarine condition. Rhyolites were divided into type-I and II based on their REE abundances and HREE fractionation. Rb–Sr and Sm–Nd isotope studies were carried out on the rock types to understand the evolution of the Dharwar Craton. Due to source heterogeneity Sm–Nd isotope system has not yielded any precise age. Rb–Sr whole-rock isochron age of 2551 ± 19 (MSWD = 1.16) Ma for BBA group could represent time of seafloor metamorphism after the formation of basaltic rocks. Magmas representing BBA group of samples do not show evidence for crustal contamination while magmas representing type-II rhyolites had undergone variable extents of assimilation of Mesoarchean continental crust (< 3.3 Ga) as evident from their initial Nd isotope values. Trace element and Nd isotope characteristics of type I rhyolites are consistent with model of generation of their magmas by partial melting of mixed sources consisting of basalt and oceanic sediments with continental crustal components. Thus this study shows evidence for presence of Mesoarchean continental crust in Peddavura area in eastern part of Dharwar Craton.

  11. Implications of a 3.472-3.333 Gyr-old subaerial microbial mat from the Barberton greenstone belt, South Africa for the UV environmental conditions on the early Earth.

    Science.gov (United States)

    Westall, Frances; de Ronde, Cornel E J; Southam, Gordon; Grassineau, Nathalie; Colas, Maggy; Cockell, Charles; Lammer, Helmut

    2006-10-29

    Modelling suggests that the UV radiation environment of the early Earth, with DNA weighted irradiances of about three orders of magnitude greater than those at present, was hostile to life forms at the surface, unless they lived in specific protected habitats. However, we present empirical evidence that challenges this commonly held view. We describe a well-developed microbial mat that formed on the surface of volcanic littoral sediments in an evaporitic environment in a 3.5-3.3Ga-old formation from the Barberton greenstone belt. Using a multiscale, multidisciplinary approach designed to strongly test the biogenicity of potential microbial structures, we show that the mat was constructed under flowing water by 0.25 microm filaments that produced copious quantities of extracellular polymeric substances, representing probably anoxygenic photosynthesizers. Associated with the mat is a small colony of rods-vibroids that probably represent sulphur-reducing bacteria. An embedded suite of evaporite minerals and desiccation cracks in the surface of the mat demonstrates that it was periodically exposed to the air in an evaporitic environment. We conclude that DNA-damaging UV radiation fluxes at the surface of the Earth at this period must either have been low (absorbed by CO2, H2O, a thin organic haze from photo-dissociated CH4, or SO2 from volcanic outgassing; scattered by volcanic, and periodically, meteorite dust, as well as by the upper layers of the microbial mat) and/or that the micro-organisms exhibited efficient gene repair/survival strategies.

  12. High-resolution quadruple sulfur isotope analyses of 3.2 Ga pyrite from the Barberton Greenstone Belt in South Africa reveal distinct environmental controls on sulfide isotopic arrays

    Science.gov (United States)

    Roerdink, Desiree L.; Mason, Paul R. D.; Whitehouse, Martin J.; Reimer, Thomas

    2013-09-01

    Multiple sulfur isotopes in Paleoarchean pyrite record valuable information on atmospheric processes and emerging microbial activity in the early sulfur cycle. Here, we report quadruple sulfur isotope data (32S, 33S, 34S, 36S) analyzed by secondary ion mass spectrometry from pyrite in a 3.26-3.23 Ga sedimentary barite deposit in the Barberton Greenstone Belt, South Africa. Our results demonstrate the presence of distinct pyrite populations and reproducible isotopic arrays in barite-free and barite-rich samples. The most 34S-depleted signatures with weakly positive Δ33S/δ34S were found in disseminated pyrite in barite, whereas positive Δ33S-values with negative Δ33S/δ34S and Δ36S/Δ33S = -0.9 ± 0.2 were exclusively observed in pyrite hosted by chert, dolomite, conglomerate and breccia. We interpret these variations to be related to local redox reactions and mixing in the sulfide phase, rather than representing primary atmospheric variability alone. The strong correlation between lithology and isotopic composition indicates distinct environments of sulfide formation linked to local sulfate concentrations and fluctuating inputs from different sulfur metabolisms. Strongly 34S-depleted sulfide was formed by microbial sulfate reduction at [SO42-] > 200 μM during deposition of barite-rich sediments, whereas isotope effects were suppressed when sulfate levels decreased during deposition of terrigeneous clastic rocks. Positive Δ33S-values indicate an increased input of sulfide derived from elemental sulfur metabolisms when sulfate concentrations fell below 200 μM. Our results support an important role for local sulfate concentrations on the expression of biogenic sulfur isotope signatures in some of the oldest rocks on Earth.

  13. Spatial greenstone-gneiss relationships: Evidence from mafic-ultramafic xenolith distribution patterns

    Science.gov (United States)

    Glikson, A. Y.

    1986-01-01

    The distribution patterns of mafic-ultramafic xenoliths within Archaean orthogneiss terrain furnish an essential key for the elucidation of granite-greenstone relations. Most greenstone belts constitute mega-xenoliths rather than primary basin structures. Transition along strike and across strike between stratigraphically low greenstone sequences and xenolith chains demonstrate their contemporaneity. These terrains represent least deformed cratonic islands within an otherwise penetratively foliated deformed gneiss-greenstone crust. Whereas early greenstone sequences are invariably intruded by tonalitic/trondhjemitic/granodioritic gneisses, stratigraphically higher successions may locally overlap older gneiss terrains and their entrained xenoliths unconformably. The contiguity of xenolith patterns suggests their derivation as relics of regional mafic-ultramafic volcanic crustal units and places limits on horizontal movements between individual crustal blocks.

  14. Granites petrology, structure, geological setting, and metallogeny

    CERN Document Server

    Nédélec, Anne; Bowden, Peter

    2015-01-01

    Granites are emblematic rocks developed from a magma that crystallized in the Earth’s crust. They ultimately outcrop at the surface worldwide. This book, translated and updated from the original French edition Pétrologie des Granites (2011) is a modern presentation of granitic rocks from magma genesis to their crystallization at a higher level into the crust. Segregation from the source, magma ascent and shapes of granitic intrusions are also discussed, as well as the eventual formation of hybrid rocks by mingling/mixing processes and the thermomechanical aspects in country rocks around granite plutons. Modern techniques for structural studies of granites are detailed extensively. Granites are considered in their geological spatial and temporal frame, in relation with plate tectonics and Earth history from the Archaean eon. A chapter on granite metallogeny explains how elements of economic interest are concentrated during magma crystallization, and examples of Sn, Cu, F and U ore deposits are presented. Mi...

  15. Geodynamic evolution of the West Africa between 2.2 and 2 Ga: the Archaean style of the Birimian greenstone belts and the sedimentary basins in northeastern Ivory-Coast; Evolution de l`Afrique de l`Ouest entre 2,2 Ga et 2 Ga: le style archeen des ceintures vertes et des ensembles sedimentaires birimiens du nord-est de la Cote-d`Ivoire

    Energy Technology Data Exchange (ETDEWEB)

    Vidal, M.; Pouclet, A. [Orleans Univ., 45 (France); Delor, C. [Bureau de Recherches Geologiques et Minieres (BRGM), 45 - Orleans (France); Simeon, Y. [ANTEA, 45 - Orleans (France); Alric, G. [Etablissements Binou, 27 - Le Mesnil-Fuguet (France)

    1996-12-31

    The litho-structural features of Palaeo-proterozoic terrains of northeastern Ivory-Coast, greenstones belts and then sedimentary (basin Birimian), are similar to those of Archaean terrains. Their early deformation is only voluminal deformation due to granitoid intrusions, mainly between 2.2 and 2.16 Ga. The shortening deformation (main deformation) is expressed by right folds and transcurrent shear zones ca 2.1 Ga. Neither thrust deformation nor high pressure metamorphic assemblages are known. This pattern of flexible and hot crust, at least between 2.2 and 2.16 Ga, is pole apart to a collisional pattern, proposed for West African Craton by some authors. The Archaean/Palaeo-proterozoic boundary would not represent a drastic change of the geodynamic evolution of the crust. (authors). 60 refs., 5 figs., 6 photos.

  16. Tectonic History and Metallogeny of the Chukchi Terrane

    Science.gov (United States)

    Byalobzhesky, S.; Goryachev, N. A.

    2004-12-01

    The Chukchi Terrane consists of the Anyui, Wrangel, Chaun and Bering Sub-Terranes; at present, it is the northern part of the Pacific Folded Belt. Its basement is composed of folded rocks of Proterozoic and Paleozoic, which crop out on Wrangel Island, the Kuul and Alyarmaut Uplifts, Chukotka and Seward Peninsulas. Early Precambrian blocks may be also present in it. The above-mentioned sub-terranes have a similar development history and are featured by the same type of Mesozoic metamorphism, magmatism and metallogeny. Its tectonic history has been as follows: 1. Late Proterozoic and Early Paleozoic (pre-Visean) magmatism, thrusting, isoclinal folding. Scarce occurrences of gold and stibnite mineralization. 2. An unconformity at the base of Visean - Mid Carboniferous section with basal conglomerates contain granite pebbles and boulders. 3. Permian uplifting (continental), reduced sedimentation. 4. Maximum sedimentation in Triassic time accompanied by Early Triassic rifting and dominating turbidite rocks. The problem is the provenance areas for large amounts of terrigenous rocks. 5. Lack of sediments characterisitc of the greatest part of early Jurassic (post-Sinemurian), middle Jurassic and late Jurassic (pre-Volgian) time periods. Uplifting is correlative with the extension stage in the South-Anyui Ocean. 6. Late Jurassic - Neocomian. Intense uplifting processes occured at the end of late Jurassic and in early Cretaceous and associated with intrusion of subduction- and collision-related granitoids (147-140 Ma). The Nutesyn marginal continental arc was forming over the southern periphery of terrane and flysch processes occurred there through Neocomian. Fault-related depressions were developing in the north of the area under consideration. Since late Jurassic, as a result of an approach (with a right-side fault shifting) of the Novosibirsk-Chukchi Super-Terrane and the northeastern edge of the Asiatic Craton, the Yuzhno-Anyui Ocean began to close from west to east

  17. Extension of the Archaean Madibe-Kraaipan granite-greenstone terrane in southeast Botswana: Constraints from gravity and magnetic data

    Science.gov (United States)

    Ramotoroko, Calistus D.; Ranganai, Rubeni T.; Nyabeze, Peter

    2016-11-01

    The main goal of this study is to use suitably processed potential field data between longitude 24°E to 26°E and latitude 25°S to 26.5°S to gain a better geological and structural understanding of the extension of the Madibe-Kraaipan granite-greenstone terrane in southeast Botswana. Specifically, 150 new gravity measurements at 2-4 km intervals are reduced and later merged with existing gravity data in Botswana and South Africa for an integrated crustal interpretation with regional aeromagnetic data. Gravity and aeromagnetic anomalies of the region present partly coincident medium to high amplitude regions alternating with low zones. Analysis of the data revealed the existence of relatively narrow Nsbnd S trending rocks of dense and high magnetic intensity extending to the village of Mmathethe, corresponding to the northern extent of the Kraaipan greenstone belt. Much of the north-central area forms a broad magnetic low and gravity high implying Kraaipan metavolcanic rocks are more extensively developed in this area than previously recognized, under a blanket of Kalahari sediments that are ∼55 m thick as indicated by borehole data. The whole area lies within an ENE-trending Pre-Transvaal dyke swarm visible on the regional aeromagnetic data and much clearer on (proprietary) high resolution aeromagnetic data. The derivative and analytic signal techniques applied for both gravity and magnetic data spatially map the greenstone belt and multiple granite plutons very well. Depth estimates obtained by the 3D Euler method in combination with two-dimensional power spectrum technique locate the high magnetic intensity horizon at around 4.0 km. The depths were further confirmed by gravity model results along two profiles across the granite-greenstone terrane in Botswana and South Africa in a W-E direction. The models show generally steep-sided bodies of comparable width with a maximum depth extent of 4.7 km for the greenstones and 4.4 km for the younger plutons. The

  18. Evolution-Motion of Crustobodies and Geotectonic Metallogeny

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Following the paper entitled A Preliminary Proposal on Crustobody Geotectonics presented by the first author to the 30th IGC in 1996, this paper further extends and elucidates the concept of crustobody in order to make a unifying study of the evolution and motion of crustal structures and to understand the law governing the formation and development of the earth'crust. In this paper the characteristics of crustobody evolution-motion are given. The authors lay emphasis on the relationship between crustobody evolution-motion and tectonic metallogeny. In the end, a multiple dynamic system of the crustobody evolution-motion is discussed from internal and external dynamic forces, and the mantle creep in internal dynamic factors is paid special attention to.

  19. Geology of East Egypt greenstone field in Neoproterozoic isoand arc: Reconstruction of Iron formation sedimentary environment.

    Science.gov (United States)

    Kiyokawa, S.; Suzuki, T.

    2015-12-01

    Geology of East Egypt greenstone-granit belt which is northern part of Nubia shield was identified neoproterozoic island arc amalgamated sections. There are several iron formation within these greenstone belt. Age data shows this iron formation may be overlaped during 700 Ma Snowball period, how ever, there is no detail report of well preserved ice related evidences. We now started detail field work for identified tectonic reconstruction, original stratigraphy around Iron formation and sedimentary environment during the iron formation sedimentation area. East Egyptian shield was divided three geology, Proterozoic greenstone complex, 700-600 Granitic domes and cover sequence (Hammamet Group). We focus three area to identified sedimentary environment of iron sedimentation. Along the north-south trend of Wadi EL Dabban area are, we named Wadi branch as West site is RW-0 ~ 12, East site is RE-0 ~ 12 from north to south. Northern area is structurally moderate, southern portion is north dipping. Southern portion was intruded by granite and several place contain granitic dikes. Northeast to eastern area are identified younger sedimentary sequence (Hammamat Group) which is unconformablly overlay on the other iron formation bearing greenstone belt. Structurally these area is divided four units. Wadi was divided by right-lateral strike-ship fault. The displacement are more than 3 km. Also north dipping faults are identified.East-West trend fault are divided two units. It is divided NE, SE, NW and NS units.SW unit is most well preserved thick sequence of the Iron formation. SW unit is well preserved iron formation sequence within thick volcaniclastics. This unit mostly north dipping around 40-60 degree. Structural repetition in not well understand. Reconstract stratigraphy in this unit is at least 4000m in thickness. 5 member is identified in this sequence. Several thin iron formations are observed with in pillow lava and volcaniclastic sequence. These very thick

  20. STRUCTURAL EVOLUTION AND METALLOGENY OF SOUTH XINJIANG METALLOGENIC BELT,JIANGXI,SOUTH CHINA

    Institute of Scientific and Technical Information of China (English)

    1996-01-01

    STRUCTURALEVOLUTIONANDMETALLOGENYOFSOUTHXINJIANGMETALLOGENICBELT,JIANGXI,SOUTHCHINALiuJishunWuYanzhiLiPeizheng(DepartmentofGe...

  1. Phanerozoic continental growth and gold metallogeny of Asia

    Science.gov (United States)

    Goldfarb, Richard J.; Taylor, Ryan D.; Collins, Gregory S.; Goryachev, Nicolay A.; Orlandini, Omero Felipe

    2014-01-01

    The Asian continent formed during the past 800 m.y. during late Neoproterozoic through Jurassic closure of the Tethyan ocean basins, followed by late Mesozoic circum-Pacific and Cenozoic Himalayan orogenies. The oldest gold deposits in Asia reflect accretionary events along the margins of the Siberia, Kazakhstan, North China, Tarim–Karakum, South China, and Indochina Precambrian blocks while they were isolated within the Paleotethys and surrounding Panthalassa Oceans. Orogenic gold deposits are associated with large-scale, terrane-bounding fault systems and broad areas of deformation that existed along many of the active margins of the Precambrian blocks. Deposits typically formed during regional transpressional to transtensional events immediately after to as much as 100 m.y. subsequent to the onset of accretion or collision. Major orogenic gold provinces associated with this growth of the Asian continental mass include: (1) the ca. 750 Ma Yenisei Ridge, ca. 500 Ma East Sayan, and ca. 450–350 Ma Patom provinces along the southern margins of the Siberia craton; (2) the 450 Ma Charsk belt of north-central Kazakhstan; (3) the 310–280 Ma Kalba belt of NE Kazakhstan, extending into adjacent NW Xinjiang, along the Siberia–Kazakhstan suture; (4) the ca. 300–280 Ma deposits within the Central Asian southern and middle Tien Shan (e.g., Kumtor, Zarmitan, Muruntau), marking the closure of the Turkestan Ocean between Kazakhstan and the Tarim–Karakum block; (5) the ca. 190–125 Ma Transbaikal deposits along the site of Permian to Late Jurassic diachronous closure of the Mongol–Okhotsk Ocean between Siberia and Mongolia/North China; (6) the probable Late Silurian–Early Devonian Jiagnan belt formed along the margin of Gondwana at the site of collision between the Yangtze and Cathaysia blocks; (7) Triassic deposits of the Paleozoic Qilian Shan and West Qinling orogens along the SW margin of the North China block developed during collision of South China

  2. Transregional lineament of Central Asia, its magmatism, metallogeny and seismicity

    Science.gov (United States)

    Sidorova, I.

    2004-12-01

    The analysis of the place and role of such large fault as Central Kyzylkum, North Nurata and South Ferghana, Atbashin, which were regarded earlier as separate independent structures led us to the idea that they are parts of a single global structure. We suggest that it should be called "Transregional lineament of Central Asia". Transregional lineament of Central Asia is multisutured long-term, and in the nodal points of some parts it is complicated by deep fault zones of «Anti Tien-Shan» trend.There are large gold ore deposits (Muruntau, Kokpatas, Kumtor) in the intersection of some of these faults. Within the lineament there are 4 mafite - ultramafite associations of different age, that are presented as isolated or combined blocks, zones and regions. The most ancient is ophiolite one (I association). Best of all it is developed in Sultanuvais and Northern Tamdytau, Uzbekistan. The second, rift association of this belt is picrite-gabbro-diabase-alkali-olivine-basalt is widespread within the belt (northern Bukantau, northern Nuratau, northern slope of the Altay ridge).The third association is peridotite-gabbroic. It is represented by the Tebinbulak intrusive of Sultanuvais. Coverings, small stocks, dikes and explosion tubes formed by potassic mafite-ultramafites ore related to much later inter-plate (P-T) occurrences of mafite-ultramafite magmatism (IY association). On Kyrgyzstan's territory the studied lineament is observed as a system of regional deep faults -Atbashi-Inylchek and Southern Ferghana, with which the ophiolite ultramafite-mafite formation is associated. The rocks have the traces of tectonic movements, which can be the ground to regard them as protrusions. Tectonically, the vast territory of Mongolia is divided into two large blocks: northern and southern. This part of the lineament called Transmongolian. This part is week studied-a special investigation was only carried out in its western part - Bulgan fault. Thus, in the presence of linear

  3. GEOLOGICAL AND GEOPHYSICAL RESEARCHES AND PERSPECTIVES OF NORHTEN BORDER LOCALITY IN YALONVARA-HATTU-TULOSS ARCHEAN GREENSTONE BELT (WESTERN KARELIA Геолого-геофизические исследования и перспективы рудоносности северной приграничной площади зеленокаменного пояса Ялонваара–Хатту–Тулос (Западная Карелия

    Directory of Open Access Journals (Sweden)

    Nilov M. Y.

    2013-02-01

    Full Text Available In West Karelia (Severny Prigranichny locality, an extension of the Hattu greenstone belt (Finland was traced and diorite-tonalite and granodiorite complexes, similar in petrochemical characteristics to the Kuittila and Viluvaara complexes, and near-N-S-trending shear-zones, favourable for gold concentration, were revealed. Gold is most likely to occur in Kadilampi-type massives, in schistosity and silicification zones in them and in their haloes. Gold ore occurrences and mineralization points, such as Kadilampi, Kuslokki, Gornoye, Soluha, Kappala and some others, were located

  4. Reworking of atmospheric sulfur in a Paleoarchean hydrothermal system at Londozi, Barberton Greenstone Belt, Swaziland

    NARCIS (Netherlands)

    Roerdink, Desiree L.; Mason, Paul R.D.; Whitehouse, Martin J.; Brouwer, Fraukje M.

    2016-01-01

    Anomalous fractionation of the minor isotopes of sulfur (δ33S, δ36S) in Archean pyrite is thought to reflect photochemical reactions in an anoxic atmosphere, with most samples falling along a reference array with δ36S/δ33S ≈ -1. Small deviations from this array record microbial sulfate reduction or

  5. Geochemistry and chronology of Se' ertengshan greenstone, Inner Mongolia

    Institute of Scientific and Technical Information of China (English)

    LIU Jianzhong; WANG Lili; ZHANG Fuqin; LI Chunlai; ZOU Yongliao; OUYANG Ziyuan; XU Lin

    2005-01-01

    This paper deals with the meta-mafic volcanic rocks of the Gongyiming iron deposit at Baotou, Inner Mongolia. The major and trace elements and REE data indicate that the meta-mafic volcanic rocks occurred in the environment similar to a modern continental rift. Sm-Nd and Rb-Sr isotopic studies indicated that the meta-basic rocks were formed during the Early Neoarchean from 2800 Ma to 2900 Ma and reworked during the Late Neoarchean (2500 Ma) by metamorphism. Because of the separation of the North China Craton from the Siberia Craton during the Middle Proterozoic ( 1600 Ma), the Rb-Sr systematics of the rocks has been changed. The Se' ertengshan greenstone seems to occur during the Middle Archean. A stable continental crust may have existed during the Paleoarchean.

  6. Application of lithogeochemistry in the assessment of nickel-sulphide potential in komatiite belts from northern Finland and Norway

    Directory of Open Access Journals (Sweden)

    G.J. Heggie

    2013-12-01

    Full Text Available This study tests the application of chalcophile elements such as nickel, copper and the platinum-group elements as indicators of nickel-sulphide prospectivity in komatiites from terranes of the Karelian Craton in northern Finland and Norway. Major element abundances reflect volcanic processes associated with the emplacement dynamics of ultramafic lavas, whereas the variable chalcophile element concentrations record the ore-forming process, mainly as an anomalous metal depletion and enrichment relative to the calculated background. Geochemical data from this study indicate that Paleoproterozoic komatiites in the Pulju Greenstone Belts and Archean komatiites in the Enontekiö area are prospective for nickel-sulphide mineralisation. Conversely, on the basis of the present dataset, ultramafic rocks from the Palaeoproterozoic Karasjok Greenstone Belt display lower prospectivity for nickel-sulphides, although potential exists if high-volume flow conduits and channels within the large volcanic flow field could be identified.

  7. Belt conveyer

    Energy Technology Data Exchange (ETDEWEB)

    Cwieczek, A.; Dembinski, C.

    1982-04-30

    The patented belt conveyor is distinguished by the fact that the rate of motion of the belt changes smoothly depending on the load: the greater the load the higher the rate. This makes it possible to prolong the service life of the belt, i.e., during idling of the conveyor it is exposed to deformation on the drive and tension drums a fewer number of times. The essence of the invention is based on the use for driving the drum of a friction transmission. One of the elements of this transmission is the drive drum of the conveyor, and the other is the drive wheel which is pressed to the inner (or outer) surface of the drum. Change in rotation velocity of the drum is reached by changing the diameter of the drive wheel. The rim of the latter has an elastic tire to which compressed air is fed. The diameter of the drive wheel depends on the quantity of air in the tire. It is set automatically by a regulating system depending on the conveyor load. Variants are patented for the belt conveyor which is distinguished by the design of the friction transmission. It contains 1, 2 or more drive wheels. It can have a cylindrical or conical inner surface of the drive drum, etc.

  8. Geochemical evidence for subduction in the early Archaean from quartz-carbonate-fuchsite mineralization, Isua Supracrustal Belt, West Greenland

    DEFF Research Database (Denmark)

    Pope, Emily Catherine; Rosing, Minik Thorleif; Bird, Dennis K.

    Quartz, carbonate and fuchsite (chromian muscovite) is a common metasomatic assemblage observed in orogenic gold systems, both in Phanerozoic convergent margin settings, and within supracrustal and greenstone belts of Precambrian rocks. Geologic and geochemical observations in younger orogenic...... systems suggest that ore-forming metasomatic fluids are derived from subduction-related devolitilization reactions, implying that orogenic Au-deposits in Archaean and Proterozoic supracrustal rock suites are related to subduction-style plate tectonics beginning early in Earth history. Justification...

  9. The discovery of the Neoarchean mafic dyke swarm in Hengshan and reinterpretation of the previous “Wutai greenstone belt”

    Institute of Scientific and Technical Information of China (English)

    李江海; 张志强; 黄雄南

    2002-01-01

    The structural mapping and section study indicate thai the "greenstone belts" in the southern to central parts of Hengshan were intensively sheared and transposed mafic dyke swarm, which originally intruded into the Neoarchean grey gneiss and nigh-pressure granulite terrain (HPGT). The HPGT is characterized by flat-dipping structures, to the south it became steep and was cut by the Dianmen mafic dyke swarm. After high-pressure; granulite-facies metamorphic event, the mafic dyke swarm occurred, and was associated with the extensional setting and reworked by the late strike-slip shearing. The zircon age dating proves that the Dianmen mafic dyke swarm was emplaced during the period between 2499±4 Ma and 2512±3 Ma, followed by late tectonothermal reworking. The Dianmen mafic dyke swarm further documents the extensional episode in the central to northern parts of North China Craton (NCC), providing the important constraint for the limit between Archean and Proterozoic and correlation between NCC and other e

  10. Tectonic Evolution of an Early Precambrian High-Pressure Granulite Belt in the North China Craton

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A large-scale high-pressure granulite belt (HPGB), more than 700 km long, is recognized within the metamorphic basement of the North China craton. In the regional tectonic framework, the Hengshan-Chengde HPGB is located in the central collision belt between the western block and eastern block, and represents the deep crustal structural level. The typical high-pressure granulite (HPG) outcrops are distributed in the Hengshan and Chengde areas. HPGs commonly occur as mafic xenoliths within ductile shear zones, and underwent multipile deformations. To the south, the Hengshan-Chengde HPGB is juxtaposed with the Wutai greenstone belt by several strike-slip shear zones. Preliminary isotopic age dating indicates that HPGs from North China were mainly generated at the end of the Neoarchaean, assocaited with tectonic assembly of the western and esatern blocks.

  11. Metallogeny of The Sierra de Guanajuato Range, Central México

    Science.gov (United States)

    Pedro F., Z. D.

    2004-12-01

    The Sierra de Guanajuato Range (SGR), trending N315° at Central México, is an orographic feature extending over a distance of 80 km. SGR comprises three well defined lithostratigraphic units: (1) a cretaceous basement including an arc-derived terrane named Guanajuato Arc (GA) made of gabbro, diorite and basaltic pillowed lava, and volcano-sedimentary rocks belonging to Arperos fore-arc basin which are geochemically anomalous in Au (0.15 ppm), Ag (3 ppm), Cu (40 ppm), Pb (50 ppm) and Zn (15 ppm); (2) Early Tertiary intrusive rocks, e.g., Comanja Granite which is affected by the presence of tourmalinized (schörl) aplito-pegmatite dykes mineralized with rare earths elements, and (3) Eocene redbeds (1,500-2000 m) and Oligocene-Miocene volcanics cover. The metallogeny of the SGR shows a multiple origin in time and space: volcano-sedimentary, granitic and volcanic, being possible to define three metallogenic epochs: cretaceous, paleocene and oligocene. Cretaceous epoch includes: (a) volcanogenic massive sulphide deposits (VMS) of bimodal-siliclastic type belonging to León-Guanajuato district; wallrock of VMS is made of felsic-internediate volcanics and black argillite; at Los Gavilanes deposit paragenesis is next: chalcopyrite > sphalerite > galena, pyrite > pyrrhotite > marcasite; grade is as follows: Au: .02-.07 g/t; Ag: 157-18.5 g/t; Cu: 2.24-0.81%, Pb: 4.16-0.03%; Zn: 10.35-3.02 %; (b) lens-shaped stratiform bodies of massive pyrite (i. ex., San Ignacio prospect; ˜ 4,000 ton) of exhalative-sedimentary origin with chalcopyrite and sphalerite microveins. Paleocene epoch includes both quartz-cordierite-sanidine veins and replacement bodies of hydrothermal metamorphic filliation (W +Se-Bi, Pb, Zn, Cu), and pyrometasomatic bodies [Cu, Pb, Zn (Ag), W] which genetically are linked to Comanja Granite emplacement. The wallrock at El Maguey mine (35,000 ton; 0.6% WO3) is made of hornfel and the vein (1.8-3.2m width) has a banding structure made of : \\{quartz & K

  12. Seat belt reminders.

    NARCIS (Netherlands)

    2008-01-01

    Seat belts are an effective way of reducing the number or road deaths and severe road injuries in crashes. Seat belt reminders warn car drivers and passengers if the seat belt is not fastened. This can be done by a visual signal or an acoustic signal or by a combination of the two. Seat belt reminde

  13. Belt attachment and system

    Science.gov (United States)

    Schneider, Abraham D.; Davidson, Erick M.

    2016-02-02

    Disclosed herein is a belt assembly including a flexible belt with an improved belt attachment. The belt attachment includes two crossbars spaced along the length of the belt. The crossbars retain bearings that allow predetermined movement in six degrees of freedom. The crossbars are connected by a rigid body that attaches to the bearings. Implements that are attached to the rigid body are simply supported but restrained in pitching rotation.

  14. New mapping near Iron Creek, Talkeetna Mountains, indicates presence of Nikolai greenstone

    Science.gov (United States)

    Schmidt, Jeanine M.; Werdon, Melanie B.; Wardlaw, Bruce R.

    2003-01-01

    Detailed geologic mapping in the Iron Creek area, Talkeetna Mountains B-5 Quadrangle, has documented several intrusive bodies and rock units not previously recognized and has extended the geologic history of the area through the Mesozoic and into the Tertiary era. Greenschist-facies metabasalt and metagabbro previously thought to be Paleozoic are intruded by Late Cretaceous to Paleocene dioritic to granitic plutons. The metabasalts are massive to amygdaloidal, commonly contain abundant magnetite, and large areas are patchily altered to epidote ± quartz. They host numerous copper oxide–copper sulfide–quartz–hematite veins and amygdule fillings. These lithologic features, recognized in the field, suggested a correlation of the metamafic rocks with the Late Triassic Nikolai Greenstone, which had not previously been mapped in the Iron Creek area. Thin, discontinuous metalimestones that overlie the metabasalt sequence had previously been assigned a Pennsylvanian(?) and Early Permian age on the basis of correlation with marbles to the north, which yielded Late Paleozoic or Permian macrofossils, or both. Three new samples from the metalimestones near Iron Creek yielded Late Triassic conodonts, which confirms the correlation of the underlying metamafic rocks with Nikolai Greenstone. These new data extend the occurrence of Nikolai Greenstone about 70 km southwest of its previously mapped extent.Five to 10 km north of the conodont sample localities, numerous microgabbro and diabase sills intrude siliceous and locally calcareous metasedimentary rocks of uncertain age. These sills probably represent feeder zones to the Nikolai Greenstone. In the Mt. Hayes quadrangle 150 km to the northeast, large sill-form mafic and ultramafic feeders (for example, the Fish Lake complex) to the Nikolai Greenstone in the Amphitheatre Mountains host magmatic sulfide nickel–copper–platinum-group-element (PGE) mineralization. This new recognition of Nikolai Greenstone and possible

  15. Correlations between the North China Craton and the Indian Shield: Constraints from regional metallogeny

    Directory of Open Access Journals (Sweden)

    Caifeng Li

    2015-11-01

    Full Text Available The correlation between the North China Craton (NCC and the Indian Shield (IND has been a hot topic in recent years. On the basis of ore deposit databases, the NCC and IND have shown broad similarity in metallogenesis from the middle Archaean to the Mesoproterozoic. The two blocks both have three major metallogenic systems: (1 the Archaean BIF metallogenic system; (2 the Paleoproterozoic Cu-Pb-Zn metallogenic system; and (3 the Mesoproterozoic Fe-Pb-Zn system. In the north margin of the NCC and the west margin of the IND, the Archaean BIF-Au-Cu-Pb-Zn deposits had the same petrogenesis and host rocks, the Paleoproterozoic Cu-Pb-Zn deposits were controlled by active belts, and the Mesoproterozoic Fe-Pb-Zn deposits were mainly related to multi-stage rifting. Matching regional mineralization patterns and geological features has established the continental assembly referred to as “NCWI”, an acronym for the north margin of the NCC (NC and the west margin of the IND (WI during the middle Archaean to the Mesoproterozoic. In this assembly, the available geological and metallogenic data from the Eastern Block and active belts of NC fit those from the Dharwar craton and the Aravalli–Delhi–Vindhyan belt of WI, respectively. Moreover, the depositional model and environment of Paleoproterozoic metasedimentary manganese deposits in NCWI implied that the assembly may be located at low latitudes, where the conditions were favorable for dissolving ice and precipitating manganese deposits.

  16. Contribution to the geology of the Niari basin: sedimentology and metallogeny of the mining region; Contribution a la geologie du Bassin du Niari sedimentologie et metallogenie de la region miniere

    Energy Technology Data Exchange (ETDEWEB)

    Bigotte, G. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1956-01-15

    This thesis is divided in two parts: a detailed petrographical and stratigraphical study of the upper layers of calcareous schist in Congo which lead to some sedimentological considerations, and a metallogenic study of the ores of Niari basin which lead to a theoretical description of the metallogeny in Congo. In the first part, after a brief description of the methods used, a petrographical survey of the rocks of the upper layers of calcareous schist of the Boko-Congo area is given as well as sedimentological conclusions and stratigraphical data. The studies and conclusions related to this limited area are extended to a region scale. A structural study and precised descriptions of this region lead to an attempt of tectonic explanation. In the second part, an inventory and description of known mineralisation points in the Niari basin are given and in particular the detailed descriptions of four deposits: La Grande-Mine, M'Passa, Diangala and Djenguile. The interpretations and conclusions are based on the study of the general characters of the mineralisation in Niari basin and its comparison with the mineralisation in Katanga (now Shaba region) and North Rhodesia (now Zambia). (M.P.)

  17. Digital Archiving of Audio Content using WINISIS and Greenstone Software: A Manual for Community Radio Managers

    OpenAIRE

    Rajasekharan , K.; Nafala, KM.

    2009-01-01

    This self-instructional handbook is aimed at helping managers of community radio stations, FM radio stations, public service broadcasting agencies and any other organisations that deal with audio files in creating prototype archives of digital audio documents. In line with the needs of the community, the manual guides users in creating their proper archives with stable, free software like WINISIS, GenISIS and Greenstone. The book also mentions the URLs from where these software can be downloa...

  18. Lap belts and three-point belts.

    NARCIS (Netherlands)

    Kampen, L.T.B. van & Edelman, A.

    1975-01-01

    Results of the swov-accident investigation prove that if there are any differences in the effectiveness of lap belts and three-point belts, these are so small that they cannot form a basis for giving preference to one type over the other. Furthermore, in spite of the results of this investigation wh

  19. MESOZOIC GRANITIC MAGMATISM AND METALLOGENY IN THE KHENTEY RANGE,MONGOLIA

    Institute of Scientific and Technical Information of China (English)

    Ochir Gerel

    2001-01-01

    @@ 1 Introduction Petrogenesis of Mesozoic granitoids in Mongolia that comprise the Mongol-Okhotsk foldbelt was studied during more than 40 years.This belt is well known province of the Mesozoic magmatism and mineralization including gold,copper and molybdenum,tin and tungsten,lead and zinc,and fluorite.In the middle of the 1950's Chen Guoda proposed the diwa theory to explain tectonic activity in Chinese platform.In Russian Far East for similar processes the activization (revivation) theory was proposed which explained intracontinental events in the Mongol-okhotsk foldbwlt.

  20. MESOZOIC GRANITIC MAGMATISM AND METALLOGENY IN THE KHENTEY RANGE,MONGOLIA

    Institute of Scientific and Technical Information of China (English)

    Ochir; Gerel

    2001-01-01

    1 Introduction  Petrogenesis of Mesozoic granitoids in Mongolia that comprise the Mongol-Okhotsk foldbelt was studied during more than 40 years.This belt is well known province of the Mesozoic magmatism and mineralization including gold,copper and molybdenum,tin and tungsten,lead and zinc,and fluorite.In the middle of the 1950's Chen Guoda proposed the diwa theory to explain tectonic activity in Chinese platform.In Russian Far East for similar processes the activization (revivation) theory was proposed which explained intracontinental events in the Mongol-okhotsk foldbwlt.……

  1. The metallogeny of Late Triassic rifting of the Alexander terrane in southeastern Alaska and northwestern British Columbia

    Science.gov (United States)

    Taylor, C.D.; Premo, W.R.; Meier, A.L.; Taggart, J.E.

    2008-01-01

    A belt of unusual volcanogenic massive sulfide (VMS) occurrences is located along the eastern margin of the Alexander terrane throughout southeastern Alaska and northwestern British Columbia and exhibits a range of characteristics consistent with a variety of syngenetic to epigenetic deposit types. Deposits within this belt include Greens Creek and Windy Craggy, the economically most significant VMS deposit in Alaska and the largest in North America, respectively. The occurrences are hosted by a discontinuously exposed, 800-km-long belt of rocks that consist of a 200- to 800-m-thick sequence of conglomerate, limestone, marine elastic sedimentary rocks, and tuff intercalated with and overlain by a distinctive unit of mafic pyroclastic rocks and pillowed flows. Faunal data bracket the age of the host rocks between Anisian (Middle Triassic) and late Norian (late Late Triassic). This metallogenic belt is herein referred to as the Alexander Triassic metallogenic belt. The VMS occurrences show systematic differences in degree of structural control, chemistry, and stratigraphic setting along the Alexander Triassic metallogenic belt that suggest important spatial or temporal changes in the tectonic environment of formation. At the southern end of the belt, felsic volcanic rocks overlain by shallow-water limestones characterize the lower part of the sequence. In the southern and middle portion of the belt, a distinctive pebble conglomerate marks the base of the section and is indicative of high-energy deposition in a near slope or basin margin setting. At the northern end of the belt the conglomerates, limestones, and felsic volcanic rocks are absent and the belt is composed of deep-water sedimentary and mafic volcanic rocks. This northward change in depositional environment and lithofacies is accompanied by a northward transition from epithermal-like structurally controlled, discontinuous, vein- and pod-shaped, Pb-Zn-Ag-Ba-(Cu) occurrences with relatively simple mineralogy

  2. Seat belt restraint system

    Science.gov (United States)

    Garavaglia, A.; Matsuhiro, D.

    1972-01-01

    Shoulder-harness and lap-belt restraint system was designed to be worn by individuals of widely different sizes and to permit normal body motion except under sudden deceleration. System is divided into two basic assemblies, lap belt and torso or shoulder harness. Inertia-activated reels immediately lock when seat experiences sudden deceleration.

  3. Radiation Belt Dynamics

    Science.gov (United States)

    2015-12-27

    Wygant, J. R., et al., “The Electric Field and Waves Instruments on the Radiation Belt Storm Probes Mission,” Space Sci. Rev., 179, 2013, pp. 183–220, doi...A. N., Li, X., Kanekal, S. G., Hudson, M. K., and Kress, B. T., “Observations of the Inner Radiation Belt: CRAND and Trapped Solar Protons,” J...1215–1228, doi:10.1002/2014JA020777. [27] Selesnick, R. S., “ Measurement of Inner Radiation Belt Electrons with Kinetic Energy Above 1 MeV,” J

  4. Technical Assessment of Greenstone toward Development of Digital Libraries in Iran

    Directory of Open Access Journals (Sweden)

    Mohammad Hassanzadeh

    2012-03-01

    Full Text Available Lack of integrated software is serious obstacle toward the development of digital libraries in Iran. Considering the problem, this research focused on Greenstone digital library software (GDLS to investigate its technical capabilities toward creating and managing digital collections in Iranian libraries. The study was conducted through evaluation research using a 9-spectrums checklist in two phases. In the first stage, experts from library and information science and computer science and in second stage, three user groups (with PhD, MA and BA degrees completed the checklist against capabilities of GDLS. Findings indicated that, there was no significant difference between two groups of specialist about capabilities of GDLS. Analyzing three user groups also approved GDLS competencies at this respect. There were some technical errors and bugs that experts proposed to be corrected toward best fitness of GDLS to Iranian collections.

  5. Dynamic characteristics of conveyor belts

    Institute of Scientific and Technical Information of China (English)

    HOU You-fu; MENG Qing-rui

    2008-01-01

    The dynamic characteristics of a belt conveyor are determined to a large extent by the properties of the belt. This paper describes experiments designed to establish the dynamic properties of belting material. The dynamic elastic modulus, viscous damping and theological constants of the belt were measured. Several properties were studied as a function of the tensile loading on the belt. These included longitudinal vibration, the natural vibration frequency in the transverse direction and the response to an impulse excitation. Vibration response was observed under several different excitation frequencies. Most of these properties have not been tested previously under conditions appropriate for the ISO/DP9856 standard. Two types of belt were tested, a steel reinforced belt and a fabric reinforced belt. The test equipment was built to provide data appropriate for designing belt conveyors. It was observed that the stress wave propagation speed increased with tensile load and that tensile load was the main factor influencing longitudinal vibrations.

  6. DESIGN TRENDS IN TIMING BELTS

    OpenAIRE

    Grzegorz DOMEK

    2014-01-01

    Paper presents the state of the art gear with timing belts. Areas of use pose new challenges for designers gear. It has materials and technologies used in the production. Has been developed algorithm of design timing belts to new applications

  7. Radiation belts of jupiter.

    Science.gov (United States)

    Stansberry, K G; White, R S

    1973-12-07

    Predictions of Jupiter's electron and proton radiation belts are based mainly on decimeter observations of 1966 and 1968. Extensive calculations modeling radial diffusion of particles inward from the solar wind and electron synchrotron radiation are used to relate the predictions and observations.

  8. Petrological and Mineralogical Study of Enclaves in Plutons in the Typical Mining Districts of Tongling,Anhui and Its Bearing on the Process of Magmatism—Metallogeny

    Institute of Scientific and Technical Information of China (English)

    杜杨松

    1999-01-01

    Two types of enclaves occur in magmatic plutons in Tongling,Anhui.Enclaves of the first type are residuals of metamorphic rocks of high amphibolite facies,and those of the other type are magmatic rocks ranging from monzonitic to dioritic in composition. A combined petrological and mineralogical study has been carried out on the two types of enclaves in order to estimate their forming conditions and analyze their relations to their hosts.so as to have an insight into the material sources of magmatic rocks and associated mineral deposits and give a clue to better understanding the mechanism of magmatism-metallogeny.This leads us to propose a new metallogenic model for strats-bound skarn-type ore deposits associated with a syntectic type of magmatic rocks.The new model can be simply summarized as partial melting of old metamorphic basement rocks at depth and accumulating,differentiating and positioning of magmas to form deep-level and shallow-level magma chambers,follower by mixing of different magmas associated with their crypto-explosion,migration of gas-bearing ore fluids and precipitation of metals in fluids within the magmas.

  9. The empty primordial asteroid belt.

    Science.gov (United States)

    Raymond, Sean N; Izidoro, Andre

    2017-09-01

    The asteroid belt contains less than a thousandth of Earth's mass and is radially segregated, with S-types dominating the inner belt and C-types the outer belt. It is generally assumed that the belt formed with far more mass and was later strongly depleted. We show that the present-day asteroid belt is consistent with having formed empty, without any planetesimals between Mars and Jupiter's present-day orbits. This is consistent with models in which drifting dust is concentrated into an isolated annulus of terrestrial planetesimals. Gravitational scattering during terrestrial planet formation causes radial spreading, transporting planetesimals from inside 1 to 1.5 astronomical units out to the belt. Several times the total current mass in S-types is implanted, with a preference for the inner main belt. C-types are implanted from the outside, as the giant planets' gas accretion destabilizes nearby planetesimals and injects a fraction into the asteroid belt, preferentially in the outer main belt. These implantation mechanisms are simple by-products of terrestrial and giant planet formation. The asteroid belt may thus represent a repository for planetary leftovers that accreted across the solar system but not in the belt itself.

  10. Kuiper Belt Occultation Predictions

    CERN Document Server

    Fraser, Wesley C; Trujillo, Chad; Stephens, Andrew W; Kavelaars, JJ; Brown, Michael E; Bianco, Federica B; Boyle, Richard P; Brucker, Melissa J; Hetherington, Nathan; Joner, Michael; Keel, William C; Langill, Phil P; Lister, Tim; McMillan, Russet J; Young, Leslie

    2013-01-01

    Here we present observations of 7 large Kuiper Belt Objects. From these observations, we extract a point source catalog with $\\sim0.01"$ precision, and astrometry of our target Kuiper Belt Objects with $0.04-0.08"$ precision within that catalog. We have developed a new technique to predict the future occurrence of stellar occultations by Kuiper Belt Objects. The technique makes use of a maximum likelihood approach which determines the best-fit adjustment to cataloged orbital elements of an object. Using simulations of a theoretical object, we discuss the merits and weaknesses of this technique compared to the commonly adopted ephemeris offset approach. We demonstrate that both methods suffer from separate weaknesses, and thus, together provide a fair assessment of the true uncertainty in a particular prediction. We present occultation predictions made by both methods for the 7 tracked objects, with dates as late as 2015. Finally, we discuss observations of three separate close passages of Quaoar to field star...

  11. Late Paleozoic tectonic evolution and concentrated mineralization in Balkhash and West Junggar, western part of the Central Asian Orogenic Belt

    Science.gov (United States)

    Dong, Shuwen; Chen, Xuanhua; Chen, Zhengle

    2016-04-01

    The Central Asia Orogenic Belt (CAOB) is an important area with significant growth of the crust and metallogeny in the Late Paleozoic. The Balkhash-Junggar tectono-metallogenic belt consists of the Balkhash, the West Junggar, and the East Junggar tectono-metallogenic belts in western part of the Central Asian Orogenic Belt (CAOB). According to the structural geological relationship, the East Junggar, the West Junggar, and the Balkhash belts are considered to be once a continuous E-W-trending tectono-metallogenic belt in Late Carboniferous. The West Junggar belt is featured with NE-trending left-lateral strike-slip faulting tectonic system (WJTS), while the left-lateral strike-slip faults are E-W-trending in the Balkhash belt. The WJTS consists of the Darabut, the Mayile, and the Baerluke faults, and the blocks among them. All these left-lateral strike-slip faults are forming due to the transition of tectonic settings from syn-collisional orogeny to post-collisional extension during the closure of the ocean (the Junggar Sea) in Late Carboniferous, with significant intrusion of batholiths and crust growth occurred in this period. These faults are truncated by the right-lateral strike-slip faults, such as the Chingiz-Junggar fault, and the Central Balkhash fault in Mesozoic. The Balkhash-Junggar tectono-metallogenic belt is important for the occurrence of many well-known super-large and large porphyry Cu-Mo deposits (such as the Kounrad, the Aktogai, the Borly, and the Baogutu deposits), large skarn Cu deposits (in the Sayak ore-filed), large rare metal deposits (such as the East Kounrad, the Zhanet, and the Akshatau deposits), and large gold deposits (such as the Hatu deposit). Zircon U-Pb ages, Re-Os isotopic dating of molybdenites, 40Ar/39Ar thermochronology of hornblendes, muscovites, biotites, and K-feldspars, and zircon and apatite fission track (FT) and (U-Th)/He dating and thermal history modeling, provide a multidisciplinary approach to constrain the whole

  12. Contrasting Cu-Au and Sn-W Granite Metallogeny through the Zircon Geochemical and Isotopic Record

    Science.gov (United States)

    Gardiner, Nicholas; Hawkesworth, Chris; Robb, Laurence; Whitehouse, Martin; Roberts, Nick; Kirkland, Chris

    2017-04-01

    Magmatic genesis and evolution - mediated by geodynamic setting - exert a primary control on the propensity of granites to be metal fertile. A revolution in our understanding of these petrogenetic processes has been made through a range of mineral-based tools, most notably the common accessory mineral zircon. There is consequently considerable interest in whether the geochemical and isotopic compositions of zircon can be applied to metallogenic problems. The paired magmatic belts of Myanmar have broadly contrasting metallogenic affinities (Sn-W versus Cu-Au), and are interpreted to have formed on the accretionary margin of the subducting Neo-Tethys Ocean. They therefore present the opportunity to geochemically compare and contrast the zircon compositions in two end-member types of granite-hosted mineral deposits generated in collisional settings. We present an integrated zircon isotope (U-Pb, Lu-Hf, O) and trace element dataset that fingerprint: (a) source; (b) redox conditions; and (c) degree of fractionation. These variables all impact on magma fertility, and our key question to address is whether they can be reliably traced and calibrated within the Myanmar zircon record. Granitoid-hosted zircons from the I-type copper arc have juvenile ɛHf (+7 to +12) and mantle-like δ18O (5.3 ‰), whereas zircons from the S-type tin belt have low ɛHf (-7 to -13) and heavier δ18O (6.2-7.7 ‰). Plotting Hf versus U/Yb reaffirms that the tin belt magmas contain greater crustal contributions than the copper arc rocks. Links between whole rock Rb/Sr and zircon Eu/Eu* highlights that the latter can be used to monitor magma fractionation in systems that crystallize plagioclase (low Sr/Y). Ce/Ce* and Eu/Eu* in zircon are thus sensitive to redox and fractionation respectively, and can be used to evaluate the sensitivity of zircons to the metallogenic affinity of their host rocks. Tin contents that exceed the solubility limit are required in order to make a magmatic

  13. Lap belt injuries in children.

    LENUS (Irish Health Repository)

    McGrath, N

    2010-07-01

    The use of adult seat belts without booster seats in young children may lead to severe abdominal, lumbar or cervical spine and head and neck injuries. We describe four characteristic cases of lap belt injuries presenting to a tertiary children\\'s hospital over the past year in addition to a review of the current literature. These four cases of spinal cord injury, resulting in significant long-term morbidity in the two survivors and death in one child, arose as a result of lap belt injury. These complex injuries are caused by rapid deceleration characteristic of high impact crashes, resulting in sudden flexion of the upper body around the fixed lap belt, and consequent compression of the abdominal viscera between the lap belt and spine. This report highlights the dangers of using lap belts only without shoulder straps. Age-appropriate child restraint in cars will prevent these injuries.

  14. SLH Timing Belt Powertrain

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, Abe

    2014-04-09

    The main goal of this proposal was to develop and test a novel powertrain solution for the SLH hydroEngine, a low-cost, efficient low-head hydropower technology. Nearly two-thirds of U.S. renewable electricity is produced by hydropower (EIA 2010). According to the U.S. Department of Energy; this amount could be increased by 50% with small hydropower plants, often using already-existing dams (Hall 2004). There are more than 80,000 existing dams, and of these, less than 4% generate power (Blankinship 2009). In addition, there are over 800 irrigation districts in the U.S., many with multiple, non-power, low-head drops. These existing, non-power dams and irrigation drops could be retrofitted to produce distributed, baseload, renewable energy with appropriate technology. The problem is that most existing dams are low-head, or less than 30 feet in height (Ragon 2009). Only about 2% of the available low-head hydropower resource in the U.S. has been developed, leaving more than 70 GW of annual mean potential low-head capacity untapped (Hall 2004). Natel Energy, Inc. is developing a low-head hydropower turbine that operates efficiently at heads less than 6 meters and is cost-effective for deployment across multiple low-head structures. Because of the unique racetrack-like path taken by the prime-movers in the SLH, a flexible powertrain is required. Historically, the only viable technological solution was roller chain. Despite the having the ability to easily attach blades, roller chain is characterized by significant drawbacks, including high cost, wear, and vibration from chordal action. Advanced carbon- fiber-reinforced timing belts have been recently developed which, coupled with a novel belt attachment system developed by Natel Energy, result in a large reduction in moving parts, reduced mass and cost, and elimination of chordal action for increased fatigue life. The work done in this project affirmatively addressed each of the following 3 major uncertainties concerning

  15. Nd-Sr isotopic geochemistry and U-Pb geochronology of the Fe granitic gneiss and Lajedo Granodiorite: implications for paleoproterozoic evolution of the Mineiro Belt, southern Sao Francisco craton, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Teixeira, Wilson [Universidade de Sao Paulo (USP), SP (Brazil). Inst. de Geociencias. Centro de Pesquisas Geocronologicas]. E-mail: wteixeir@usp.br; Avila, Ciro Alexandre [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Museu Nacional. Dept. de Geologia e Paleontologia]. E-mail: avila@mn.ufrj.br; Nunes, Luciana Cabral [Universidade de Sao Paulo (USP), SP (Brazil). Inst. de Geociencias]. E-mail: luciana@igc.usp.br

    2008-07-01

    The Fe granitic gneiss and Lajedo granodiorite belong to a voluminous felsic-mafic plutonism, tectonically linked to Paleoproterozoic magmatic evolution of the Mineiro Belt, southern portion of the Sao Francisco Craton, central-eastern Brazil. The Fe pluton is located north of the Lenheiros shear zone and is intrusive with respect to the Rio das Mortes greenstone belt and pyroxenite - gabbroic bodies, as indicated by xenoliths of gneiss and amphibolite, in the first case, and pyroxenite in the latter. The Lajedo granodiorite is located south of the Lenheiros shear zone and cuts the metamafic rocks of the Forro peridotite - pyroxenite and mafic and intermediate rocks of the Nazareno greenstone belt, as evidenced by xenoliths from the latter unit. The modal composition of the Fe granitic gneiss lies within the ranges of monzogranite and syenogranite. It is peraluminous and shows a large variation in K{sub 2}O content, which implies a middle-K calc-alkaline to high-K calc-alkaline tendency. The Lajedo modal composition is consistent with granodioritic and tonalitic compositions. It indicates a predominantly peraluminous composition and calc-alkaline character. The U-Pb zircon crystallization age of the Fe granitic gneiss is 2191 {+-} 9 Ma, whereas the Lajedo granodiorite yields 2208 {+-} 26 Ma. The Nd/Sr characteristics of the Fe and Lajedo plutons are consistent with mixtures of enriched mantle (EMI-type), DMM and crustal components during magma genesis in a plutonic arc setting, while the low {sup 87}Sr/{sup 86}Sri ratios point to contribution of mafic rock protoliths during magma genesis. This is also in accordance with the characteristic xenoliths observed within the investigated plutons from the Nazareno and Rio das Mortes greenstone belts. The Fe granitic gneiss and Lajedo granodiorite show tectonic characteristics which are comparable to those of nearby coeval plutons: Brito quartz-diorite (2221 +- 2 Ma), Brumado de Cima granodiorite (2219 {+-} 2 Ma), Brumado

  16. Coronal radiation belts

    CERN Document Server

    Hudson, H S; Frewen, S F N; DeRosa, M L

    2009-01-01

    The magnetic field of the solar corona has a large-scale dipole character, which maps into the bipolar field in the solar wind. Using standard representations of the coronal field, we show that high-energy ions can be trapped stably in these large-scale closed fields. The drift shells that describe the conservation of the third adiabatic invariant may have complicated geometries. Particles trapped in these zones would resemble the Van Allen Belts and could have detectable consequences. We discuss potential sources of trapped particles.

  17. Dunlop Enerka Belting supplies and installs Europe's longest conveyor belt at British Coal-Mine

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    @@ Dunlop Enerka Belting of Farington, U.K., has supplied a steel cord conveyor belt to the mine complex at Selby in North Yorkshire operated by RJB Mining plc. The new conveyor belt replaces the belt supplied and installed in 1981 by Dunlop Enerka Belting (then BTR Belting Ltd.).

  18. DESIGN TRENDS IN TIMING BELTS

    Directory of Open Access Journals (Sweden)

    Grzegorz DOMEK

    2014-03-01

    Full Text Available Paper presents the state of the art gear with timing belts. Areas of use pose new challenges for designers gear. It has materials and technologies used in the production. Has been developed algorithm of design timing belts to new applications

  19. Geography of the asteroid belt

    Science.gov (United States)

    Zellner, B. H.

    1978-01-01

    The CSM classification serves as the starting point on the geography of the asteroid belt. Raw data on asteroid types are corrected for observational biases (against dark objects, for instance) to derive the distribution of types throughout the belt. Recent work on family members indicates that dynamical families have a true physical relationship, presumably indicating common origin in the breakup of a parent asteroid.

  20. 中国钨矿成矿规律概要%Outline of Metallogeny of Tungsten Deposits in China

    Institute of Scientific and Technical Information of China (English)

    盛继福; 陈郑辉; 刘丽君; 应立娟; 黄凡; 王登红; 王家欢; 曾乐

    2015-01-01

    Tungsten mineral resources are abundant with relatively complete types of deposits,including the larger tungsten reservers of skarn-type and quartz vein-type,and the most important wolframite-quartz vein type in terms of exploitation and utilization.The skarn-type tungsten deposits centralize in central Nanling region such as south Hunan Province,while quartz vein-type tungsten depostis are concentrated in South China.The most important metallogenic age of tungsten is Mesozoic,while the metallogenic tectonic setting is featured by intra continental environment after orogeny with severe tectonic movements,deep-seated faults and frequent magmatic activities,especially Mesozoic granitoids closely to tungsten-tin mineralization.Besides,22 metallogenic series of ore deposits significantly related with tungsten have been defined,based on statistics precise information system of 1199 tungsten mining areas and thorough summary of metallogenic regularity.On the studies of metallogenic regularity of tungsten deposits,the skarn-type (or greisen type),quartz vein-type and massif-type of tungsten deposits are thought to be key prediction types,65 tungsten-forming belts and 22 key ore concentration areas displayed in the distribution map of tungsten-forming belts are devided in China.Generally,the whole work provides theoretical basis for the potential evaluation.%我国钨矿资源丰富,钨矿类型比较齐全。占有钨矿资源储量较大比重的主要是矽卡岩型和石英脉型,但从开采和利用的角度来说,最为重要的是石英脉型的黑钨矿矿床。矽卡岩型钨矿集中分布在南岭中段湘南、东秦岭等矿集区,石英脉型则主要集中在华南地区的闽西、赣南、粤北、湘南等地;成矿时代以中生代最为重要;成矿大地构造背景以造山运动之后的陆内环境为主但构造变动剧烈,深大断裂纵横交错,岩浆活动频繁,与钨锡成矿作用密切相关的中生代花岗岩类至

  1. Field and geochemical characterisitics of the Mesoarchean (~3075 ma) Ivisaartoq greenstone belt, southern West Greenland: Evidence for seafloor hydrothermal alteration in a supra-subduction oceanic crust

    DEFF Research Database (Denmark)

    Polat, A.; Appel, P.W.U.; Frei, Robert

    2006-01-01

    assemblage is interpreted as relict epidosite. The stage II metasomatic assemblage occurs as concordant discontinuous layered calc-silicate bodies to discordant calc-silicate veins commonly associated with shear zones. The stage II metasomatic assemblage consists mainly of diopside...... + garnet + amphibole + plagioclase + quartz ± vesuvianite ± scapolite ± epidote ± titanite ± calcite ± scheelite. Given that the second stage of metasomatism is closely associated with shear zones and replaced rocks with an early metamorphic fabric, its origin is attributed to regional dynamothermal metamorphism. The least altered pillow basalts, picrites, gabbros, and diorites are characterized by LREE......-enriched, near-flat HREE, and HFSE (especially Nb)-depleted trace element patterns, indicating a subduction zone geochemical signature. Ultramafic pillows and cumulates display large positive initial eNd values of + 1.3 to + 5.0, consistent with a strongly depleted mantle source. Given the geological...

  2. Geochemical characteristics of gold bearing boninites and banded iron formations from Shimoga greenstone belt, India: Implications for gold genesis and hydrothermal processes in diverse tectonic settings

    Digital Repository Service at National Institute of Oceanography (India)

    Ganguly, S.; Manikyamba, C.; Saha, A.; Lingadevaru, M.; Santosh, M.; Rambabu, S.; Khelen, A.C.; Purushotham, D.; Linga, D.

    of these rocks, based on MgO, TiO2 Ni, Cr and Co contents, Al2O3/TiO2, (Gd/Yb)N and (La/Sm)N ratios, classify them as boninites and their relative LILE-HFSE abundance suggests magma generation...

  3. Synchrotron Radiation X-Ray Fluorescence nanoanalyses of the metallome of a ~3.3 Ga-old microbial biofilm from the Barberton greenstone belt, South Africa.

    Science.gov (United States)

    Hubert, A.; Lemelle, L.; Salome, M.; Cloetens, P.; Westall, F.; Simionovici, A.

    2012-04-01

    Combining in situ nanometer-scale techniques on the fossilized Josefsdal Chert Microbial Biofilm (JCMB) reveals a distinct vertical structural and compositional organisation: the lower part is calcified as aragonite, while the upper non-calcified kerogenous layer is characterised by up to 1% sulphur [1]. The in situ analysis of all the metals as a group represents a useful microbial fingerprint [2] and we will continue to explore it. Synchrotron Radiation X-Ray Fluorescence maps of high spatial resolution (AIP Conference Proceedings, 1221, 131-138. 4. Bleuet P., et al., 2008. App. Phys. Lett., 92, 213111-1-3. 5. Golosio B., et al., 2003. Appl. Phys., 94, 145-157. 6. M. Haschke, 2003. PhD dissertation, T.U. Berlin. 7. Simionovici A. S., et al., 2010. Proceedings of the Meteoritical Society Conference, N.Y., USA. 8. Solé V.A., et al., 2006, Elsevier, 62, 63-68.

  4. Iron and sulfur isotope constraints on redox conditions associated with the 3.2 Ga barite deposits of the Mapepe Formation (Barberton Greenstone Belt, South Africa)

    Science.gov (United States)

    Busigny, Vincent; Marin-Carbonne, Johanna; Muller, Elodie; Cartigny, Pierre; Rollion-Bard, Claire; Assayag, Nelly; Philippot, Pascal

    2017-08-01

    The occurrence of Early Archean barite deposits is intriguing since this type of sediment requires high availability of dissolved sulfate (SO42-), the oxidized form of sulfur, although most authors argued that the Archean eon was dominated by reducing conditions, with low oceanic sulfate concentration (gases produced by large subaerial volcanic events, and possibly SO42- produced by magmatic SO2 disproportionation in hydrothermal systems.

  5. Evaluation of the static belt fit provided by belt-positioning booster seats.

    Science.gov (United States)

    Reed, Matthew P; Ebert, Sheila M; Sherwood, Christopher P; Klinich, Kathleen D; Manary, Miriam A

    2009-05-01

    Belt-positioning booster seats are recommended for children who use vehicle seat belts as primary restraints but who are too small to obtain good belt fit. Previous research has shown that belt-positioning boosters reduce injury risk, but the belt fit produced by the wide range of boosters in the US market has not previously been assessed. The present study describes the development of a method for quantifying static belt fit with a Hybrid-III 6-year-old test dummy. The measurement method was applied in a laboratory seat mockup to 31 boosters (10 in both backless and highback modes) across a range of belt geometries obtained from in-vehicle measurements. Belt fit varied widely across boosters. Backless boosters generally produced better lap belt fit than highback boosters, largely because adding the back component moved the dummy forward with respect to the lap belt routing guides. However, highback boosters produced more consistent shoulder belt fit because of the presence of belt routing guides near the shoulder. Some boosters performed well on both lap belt and shoulder belt fit. Lap belt fit in dedicated boosters was generally better than in combination restraints that also can be used with an integrated harness. Results demonstrate that certain booster design features produce better belt fit across a wide range of belt geometries. Lap belt guides that hold the belt down, rather than up, and shoulder belt guides integrated into the booster backrest provided better belt fit.

  6. AUTOMATION OF CONVEYOR BELT TRANSPORT

    Directory of Open Access Journals (Sweden)

    Nenad Marinović

    1990-12-01

    Full Text Available Belt conveyor transport, although one of the most economical mining transport system, introduce many problems to mantain the continuity of the operation. Every stop causes economical loses. Optimal operation require correct tension of the belt, correct belt position and velocity and faultless rolls, which are together input conditions for automation. Detection and position selection of the faults are essential for safety to eliminate fire hazard and for efficient maintenance. Detection and location of idler roll faults are still open problem and up to now not solved successfully (the paper is published in Croatian.

  7. Seat Belt Use and Stress in Adolescents.

    Science.gov (United States)

    Schichor, Aric; And Others

    1990-01-01

    Explored adolescent seat belt use and psychosocial risk factors in urban minority population (n=541). Found seat belt use reported by 49 percent of respondents. Those reporting no or intermittent seat belt use were significantly more likely than seat belt users to feel down, have decreased home support, have problems with school and the law, and…

  8. 49 CFR 393.93 - Seats, seat belt assemblies, and seat belt assembly anchorages.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Seats, seat belt assemblies, and seat belt... § 393.93 Seats, seat belt assemblies, and seat belt assembly anchorages. (a) Buses—(1) Buses... the driver's seat and seat belt assembly anchorages that conform to the location and...

  9. Chaos on the conveyor belt

    CERN Document Server

    Sándor, Bulcsú; Tél, Tamás; Néda, Zoltán

    2013-01-01

    The dynamics of a spring-block train placed on a moving conveyor belt is investigated both by simple experiments and computer simulations. The first block is connected by spring to an external static point, and due to the dragging effect of the belt the blocks undergo complex stick-slip dynamics. A qualitative agreement with the experimental results can only be achieved by taking into account the spatial inhomogeneity of the friction force on the belt's surface, modeled as noise. As a function of the velocity of the conveyor belt and the noise strength, the system exhibits complex, self-organized critical, sometimes chaotic dynamics and phase transition-like behavior. Noise induced chaos and intermittency is also observed. Simulations suggest that the maximum complexity of the dynamical states is achieved for a relatively small number of blocks, around five.

  10. Hydrothermal Mineralization on the Mesoproterozoic Passive Continental Margins of China:A Case Study of the Langshan-Zha'ertaishan Belt, Inner Mongolia, China

    Institute of Scientific and Technical Information of China (English)

    PENG Runmin; ZHAI Yusheng

    2004-01-01

    Most ore-forming characteristics of the Langshan-Zha'ertaishan hydrothermal exhalation belt, which consists of the Dongshengmiao, Huogeqi, Tanyaokou and Jiashengpan large-superlarge Zn-Pb-Cu-Fe sulfide deposits, are most similar to those of Mesoproterozoic SEDEX-type provinces of the world. The characteristics include: (1) All deposits of this type in the belt occur in third-order fault-basins in the Langshan-Zha'ertaishan aulacogen along the northern margin of the North China Platform; (2) these deposits with all their orebodies hosted in the Mesoproterozoic impure dolomite-marble and carbonaceous phyllite (or schists) have an apparent stratabound nature; ores display laminated and banded structures,showing clear depositional features; (3) there is some evidence of syn-sedimentary faulting, which to a certain extent accounts for the temporal and spatial distribution and the size of the orebodies in all deposits and the formation of intrabed conglomerates and breccias; (4) they show lateral and vertical zonation of sulfides; (5) The Cu/(Pb+Zn+Cu) ratio of the large and thick Pb+Zn+Cu orebodies gradually decreases from bottom to top; and (6) barite is interbedded with pyrites and sometimes with sphalerite. However, some characteristics such as the Co/Ni radio of the pyrites, the volcanism, for example, of the Langshan-Zha'ertaishan metallogenic belt, are different from those of the typical SEDEX deposits of the world. The meta-basic volcanic rock in Huogeqi, the sodic bimodal volcanic rocks in the Dongshengmiao and potassic bimodal-volcanic rocks with blastoporphyritic and blasto-glomeroporphyritic texture as well as blasto-amygdaloidal structure in the Tanyaokou deposits have been discovered in the only ore-bearing second formation of the Langshan Group in the past 10 years. The metallogeny of some deposits hosted in the Langshan Group is closely related to syn-sedimentary volcanism based on the following facts: most of the lead isotopes in sphalerite, galena

  11. Northern Belt of Jupiter

    Science.gov (United States)

    2000-01-01

    [figure removed for brevity, see original site] A four-panel frame shows a section of Jupiter's north equatorial belt viewed by NASA's Cassini spacecraft at four different wavelengths, and a separate reference frame shows the location of the belt on the planet.A fascinating aspect of the images in the four-panel frame is the small bright spot in the center of each. The images come from different layers of the atmosphere, so the spot appears to be a storm penetrating upward through several layers. This may in fact be a 'monster' thunderstorm, penetrating all the way into the stratosphere, as do some summer thunderstorms in the midwestern United States. These images were taken on Nov. 27, 2000, at a resolution of 192 kilometers (119 miles) per pixel. They have been contrast-enhanced to highlight features in the atmosphere.The top panel of the four-panel frame is an image taken in a near-infrared wavelength at which the gases in Jupiter's atmosphere are relatively non-absorbing. Sunlight can penetrate deeply into the atmosphere at this wavelength and be reflected back out, providing a view of an underlying region of the atmosphere, the lower troposphere.The second panel was taken in the blue portion of wavelengths detected by the human eye. At these wavelengths, gases in the atmosphere scatter a modest amount of sunlight, so the clouds we see tend to be at somewhat higher altitudes than in the top panel.The third panel shows near-infrared reflected sunlight at a wavelength where the gas methane, an important constituent of Jupiter's atmosphere, absorbs strongly. Dark places are regions without high-level clouds and consequently large amounts of methane accessible to sunlight. Bright regions are locations with high clouds in the upper troposphere shielding the methane below.The bottom panel was taken in the ultraviolet. At these very short wavelengths, the clear atmosphere scatters sunlight, and hazes in the stratosphere, above the troposphere, absorb sunlight. That

  12. The origin of carbonaceous matter in pre-3.0 Ga greenstone terrains: A review and new evidence from the 3.42 Ga Buck Reef Chert

    Science.gov (United States)

    Tice, Michael M.; Lowe, Donald R.

    2006-06-01

    The geological record of carbonaceous matter from at least 3.5 Ga to the end of the Precambrian is fundamentally continuous in terms of carbonaceous matter structure, composition, environments of deposition/preservation, and abundance in host rocks. No abiotic processes are currently known to be capable of producing continuity in all four of these properties. Although this broad view of the geological record does not prove that life had arisen by 3.5 Ga, the end of the early Archean, it suggests a working hypothesis: most if not all carbonaceous matter present in rocks older than 3.0 Ga was produced by living organisms. This hypothesis must be tested by studies of specific early geological units designed to explore the form, distribution, and origin of enclosed carbonaceous matter. The carbonaceous, environmentally diverse 3416 Ma Buck Reef Chert (BRC) of the Barberton greenstone belt, South Africa, provides an opportunity for such a study. Upward facies progressions in the BRC reflect deposition in environments ranging from shallow marine evaporitic brine ponds to a storm- and wave-active shelf to a deep, low-energy basinal setting below storm wave base. Abundances and ratios of Al 2O 3, Zr, TiO 2, and Cr track inputs of various types of volcaniclastic and terrigenous clastic materials. In particular, Zr/Al 2O 3 and Zr serve as proxies for concentration of windblown dust and, indirectly, as proxies for sedimentation rate. Cu, Zn, Ni, and FeO were concentrated in the most slowly deposited transitional and basinal sediments, inconsistent with a hydrothermal setting but consistent with a normal marine setting. The distribution of microfacies defined by associations and layering of clastic, ferruginous, and carbonaceous grains correlates with facies transitions. Fine carbonaceous laminations, which occur only in shallow platform settings, represent photosynthetic microbial mats. These were ripped up and the debris widely redistributed in shallow and deep water by

  13. The Zimbabwe Craton in Mozambique: A brief review of its geochronological pattern and its relation to the Mozambique Belt

    Science.gov (United States)

    Chaúque, F. R.; Cordani, U. G.; Jamal, D. L.; Onoe, A. T.

    2017-05-01

    The eastern margin of the Zimbabwe Craton, along the Mozambique-Zimbabwe border, includes the oldest rocks of west-central Mozambique constituting a large terrain of granite-greenstone type dated between 3000 and 2500 Ma. These rocks consist mainly of gneisses and granitoid rocks of tonalitic-trondhjemitic-granodioritic composition belonging to the Mudzi Metamorphic Complex in the northern part and to the Mavonde Complex in the southern part. The latter is associated with a granite-greenstone terrain, which includes the eastern part of Mutare-Odzi-Manica greenstone belt. A volcano-sedimentary sequences cover, belonging to the apparently Mesoproterozoic and Paleoproterozoic Umkondo and Gairezi groups respectively was deposited along the eastern margin of the craton and is exposed in the territory of Mozambique. The Umkondo minimum age is marked by intrusive dolerite in Zimbabwe dated at 1100 Ma while for the Ghairezi it is still not well established. The Gairezi Group was subjected to progressive metamorphism of Pan-African age. At the margin of the Zimbabwe Craton, in its northern part, metasedimentary units occur representing a passive margin of Neoproterozoic age. They make up the Rushinga Group, which includes felsic metavolcanic rocks dated at ca.800 Ma. Granulites and medium- to high-grade paragneisses, and migmatites of the Chimoio, Macossa and Mungari Groups of Neoproterozoic metamorphic age, overly the ortho-metamorphic pre-existing rock of ca. 1100 Ma, which belongs to the Báruè Magmatic Arc. They characterize the N-S trend Mozambique Belt, which appears to the east of the craton tectonically juxtaposed on the Archean rocks. The maximum age of deposition of these rocks, indicated by U-Pb dating of detrital zircons, is ca. 700 Ma and their minimum age is limited by a few monzonitic Cambrian intrusions dated at ca. 500 Ma. The Neoproterozoic bimodal Guro Suite, dated at ca. 850 Ma and composed of felsic and mafic members characterizes the east

  14. Effects of vehicle seat and belt geometry on belt fit for children with and without belt positioning booster seats.

    Science.gov (United States)

    Reed, Matthew P; Ebert-Hamilton, Sheila M; Klinich, Kathleen D; Manary, Miriam A; Rupp, Jonathan D

    2013-01-01

    A laboratory study was conducted to quantify the effects of belt-positioning boosters on lap and shoulder belt fit. Postures and belt fit were measured for forty-four boys and girls ages 5-12 in four highback boosters, one backless booster, and on a vehicle seat without a booster. Belt anchorage locations were varied over a wide range. Seat cushion angle, seat back angle, and seat cushion length were varied in the no-booster conditions. All boosters produced better mean lap belt fit than was observed in the no-booster condition, but the differences among boosters were relatively large. With one midrange belt configuration, the lap belt was not fully below the anterior-superior iliac spine (ASIS) landmark on the front of the pelvis for 89% of children in one booster, and 75% of children failed to achieve that level of belt fit in another. In contrast, the lap belt was fully below the ASIS for all but two children in the best-performing booster. Child body size had a statistically significant but relatively small effect on lap belt fit. The largest children sitting without a booster had approximately the same lap belt fit as the smallest children experienced in the worst-performing booster. Increasing lap belt angle relative to horizontal produced significantly better lap belt fit in the no-booster condition, but the boosters isolated the children from the effects of lap belt angles. Reducing seat cushion length in the no-booster condition improved lap belt fit but changing cushion angle did not. Belt upper anchorage (D-ring) location had a strong effect on shoulder belt fit in conditions without shoulder belt routing from the booster. Unexpectedly, the worst average shoulder belt fit was observed in one highback booster with a poorly positioned shoulder belt routing clip. The shoulder belt was routed more outboard, on average, with a backless booster than without a booster, but raising the child also amplified the effect of D-ring location, such that children were

  15. Kuiper Belts Around Nearby Stars

    CERN Document Server

    Nilsson, R; Brandeker, A; Olofsson, G; Pilbratt, G L; Risacher, C; Rodmann, J; Augereau, J -C; Bergman, P; Eiroa, C; Fridlund, M; Thébault, P; White, G J

    2010-01-01

    In order to detect and characterise cold extended circumstellar dust originating from collisions of planetesimal bodies in disks, belts, or rings at Kuiper-Belt distances (30--50\\,AU or beyond) sensitive submillimetre observations are essential. Measurements of the flux densities at these wavelengths will extend existing IR photometry and permit more detailed modelling of the Rayleigh-Jeans tail of the disks spectral energy distribution (SED), effectively constraining dust properties and disk extensions. By observing stars spanning from a few up to several hundred Myr, the evolution of debris disks during crucial phases of planet formation can be studied. // We have performed 870\\,$\\mu$m observations of 22 exo-Kuiper-Belt candidates, as part of a Large Programme with the LABOCA bolometer at the APEX telescope. Dust masses (or upper limits) were calculated from integrated 870\\,$\\mu$m fluxes, and fits to the SED of detected sources revealed the fractional dust luminosities $f_{\\mathrm{dust}}$, dust temperatures...

  16. The Wisconsin magmatic terrane: An Early Proterozoic greenstone-granite terrane formed by plate tectonic processes

    Science.gov (United States)

    Schulz, K. J.; Laberge, G. L.

    1986-01-01

    The Wisconsin magmatic terrane (WMT) is an east trending belt of dominantly volcanic-plutonic complexes of Early Proterozoic age (approx. 1850 m.y.) that lies to the south of the Archean rocks and Early Proterozoic epicratonic sequence (Marquette Range Supergroup) in Michigan. It is separated from the epicratonic Marquette Range Supergroup by the high-angle Niagara fault, is bounded on the south, in central Wisconsin, by Archean gneisses, is truncated on the west by rocks of the Midcontinent rift system, and is intruded on the east by the post-orogenic Wolf river batholith. The overall lithologic, geochemical, metallogenic, metamorphic, and deformational characteristics of the WMT are similar to those observed in recent volcanic arc terranes formed at sites of plate convergence. It is concluded that the WMT represents an evolved oceanic island-arc terrane accreated to the Superior craton in the Early Proterozoic. This conclusion is strengthened by the apparent absence of Archean basement from most of the WMT, and the recent recognition of the passive margin character of the epicratonic Marquette Range Supergroup.

  17. Timing of multiple hydrothermal events in the iron oxide-copper-gold deposits of the Southern Copper Belt, Carajás Province, Brazil

    Science.gov (United States)

    Moreto, Carolina P. N.; Monteiro, Lena V. S.; Xavier, Roberto P.; Creaser, Robert A.; DuFrane, S. Andrew; Melo, Gustavo H. C.; Delinardo da Silva, Marco A.; Tassinari, Colombo C. G.; Sato, Kei

    2015-06-01

    The Southern Copper Belt, Carajás Province, Brazil, hosts several iron oxide-copper-gold (IOCG) deposits, including Sossego, Cristalino, Alvo 118, Bacuri, Bacaba, Castanha, and Visconde. Mapping and U-Pb sensitive high-resolution ion microprobe (SHRIMP) IIe zircon geochronology allowed the characterization of the host rocks, situated within regional WNW-ESE shear zones. They encompass Mesoarchean (3.08-2.85 Ga) TTG orthogneiss, granites, and remains of greenstone belts, Neoarchean (ca. 2.74 Ga) granite, shallow-emplaced porphyries, and granophyric granite coeval with gabbro, and Paleoproterozoic (1.88 Ga) porphyry dykes. Extensive hydrothermal zones include albite-scapolite, biotite-scapolite-tourmaline-magnetite alteration, and proximal potassium feldspar, chlorite-epidote and chalcopyrite formation. U-Pb laser ablation multicollector inductively coupled mass spectrometry (LA-MC-ICP-MS) analysis of ore-related monazite and Re-Os NTIMS analysis of molybdenite suggest multiple Neoarchean (2.76 and 2.72-2.68 Ga) and Paleoproterozoic (2.06 Ga) hydrothermal events at the Bacaba and Bacuri deposits. These results, combined with available geochronological data from the literature, indicate recurrence of hydrothermal systems in the Southern Copper Belt, including 1.90-1.88-Ga ore formation in the Sossego-Curral ore bodies and the Alvo 118 deposit. Although early hydrothermal evolution at 2.76 Ga points to fluid migration coeval with the Carajás Basin formation, the main episode of IOCG genesis (2.72-2.68 Ga) is related to basin inversion coupled with Neoarchean (ca. 2.7 Ga) felsic magmatism. The data suggest that the IOCG deposits in the Southern Copper Belt and those in the Northern Copper Belt (2.57-Ga Salobo and Igarapé Bahia-Alemão deposits) do not share a common metallogenic evolution. Therefore, the association of all IOCG deposits of the Carajás Province with a single extensive hydrothermal system is precluded.

  18. Appendiceal transection associated with seat belt restraint.

    Science.gov (United States)

    Go, Seung Je; Sul, Young Hoon; Ye, Jin Bong; Kim, Joong Suck

    2016-08-01

    The seat belt is designed for safety in a motor vehicle and should be worn to prevent severe injuries. But, the seat belt itself can be an injury factor in combination with deceleration forces applied to fixation points of mobile viscera. Here, we present a 23-year-man with traumatic transection of the appendix, highly mobile viscera, following seat belt injury.

  19. French experience in seat belt use.

    NARCIS (Netherlands)

    Lassarre, S. & Page, Y.

    1992-01-01

    This paper concerns the French experience in seat belt use. As well as the seat belt regulations, the strategies employed to reinforce the wearing of seat belts by using information and encouragement campaigns and checks by the police and gendarmerie are described here along with their timetables an

  20. Kuiper belts around nearby stars

    NARCIS (Netherlands)

    Nilsson, R.; Liseau, R.; Brandeker, A.; Olofsson, G.; Pilbratt, G. L.; Risacher, C.; Rodmann, J.; Augereau, J-C.; Bergman, P.; Eiroa, C.; Fridlund, M.; Thebault, P.; White, G. J.

    2010-01-01

    Context. The existence of dusty debris disks around a large fraction of solar type main-sequence stars, inferred from excess far-IR and submillimetre emission compared to that expected from stellar photospheres, suggests that leftover planetesimal belts analogous to the asteroid-and comet reservoirs

  1. Visible and infrared properties of unaltered to weathered rocks from Precambrian granite-greenstone terrains of the West African Craton

    Science.gov (United States)

    Metelka, Václav; Baratoux, Lenka; Jessell, Mark W.; Naba, Séta

    2015-12-01

    In situ and laboratory 0.35 μm-2.5 μm spectra of rocks from a Paleoproterozoic granite-greenstone terrain along with its Neoproterozoic sedimentary cover and derived regolith materials were examined in western Burkina Faso. The reflectance spectra show the influence of typical arid to semi-arid weathering with the formation of desert varnish, iron films, and dust coatings. Fe and Mg-OH absorption features related to chlorite, amphibole, pyroxene, epidote, and biotite are observable in the mafic and intermediate meta-volcanic rocks as well as in the granodiorites and tonalites. Al-OH absorption caused by kaolinite, smectite, illite/muscovite are typical for meta-volcano-sedimentary schists, Tarkwaian-type detrital meta-sediments, sandstones of the Taoudeni basin, all of the weathered surfaces and regolith materials. Ferric and ferrous iron absorptions related to both primary rock-forming minerals and secondary weathering minerals (goethite, hematite) were observed in most of the sampled materials. The results show that although weathering alters the spectral signature of the fresh rock, indicative absorption features located in the short wave infrared region remain detectable. In addition, spectra of soils partially reflect the mineral composition of the weathered rock surfaces. The analysis of the hyperspectral data shows the potential of differentiating between the sampled surfaces. The library presents a primary database for the geological and regolith analysis of remote sensing data in West Africa.

  2. Seat belt sign and its significance.

    Science.gov (United States)

    Agrawal, Amit; Inamadar, Praveenkumar Ishwarappa; Subrahmanyam, Bhattara Vishweswar

    2013-07-01

    Safety belts are the most important safety system in motor vehicles and when worn intend to prevent serious injuries. However, in unusual circumstances (high velocity motor vehicle collisions) these safety measures (seat belts) can be the source and cause of serious injuries. The seat belt syndrome was first described as early by Garrett and Braunste in but the term "seat belt sign" was discussed by Doersch and Dozier. Medical personnel's involved in emergency care of trauma patients should be aware of seat belt sign and there should a higher index of suspicion to rule out underlying organ injuries.

  3. Ring current and radiation belts

    Science.gov (United States)

    Williams, D. J.

    1987-01-01

    Studies performed during 1983-1986 on the ring current, the injection boundary model, and the radiation belts are discussed. The results of these studies yielded the first observations on the composition and charge state of the ring current throughout the ring-current energy range, and strong observational support for an injection-boundary model accounting for the origins of radiation-belt particles, the ring current, and substorm particles observed at R less than about 7 earth radii. In addition, the results have demonstrated that the detection of energetic neutral atoms generated by charge-exchange interactions between the ring current and the hydrogen geocorona can provide global images of the earth's ring current and its spatial and temporal evolution.

  4. Saturation of Van Allen's belts

    CERN Document Server

    Le Bel, E

    2002-01-01

    The maximum number of electrons that can be trapped in van Allen's belts has been evaluated at CEA-DAM more precisely than that commonly used in the space community. The modelization that we have developed allows to understand the disagreement (factor 50) observed between the measured and predicted electrons flux by US satellites and theory. This saturation level allows sizing-up of the protection on a satellite in case of energetic events. (authors)

  5. Intelligent seat belt reminders-do they change driver seat belt use in Europe?

    Science.gov (United States)

    Lie, Anders; Krafft, Maria; Kullgren, Anders; Tingvall, Claes

    2008-10-01

    Many modern cars have seat belt reminders (SBRs) using loud and clear sound and light signals. These systems have developed over the last few years. This study investigates how these modern systems influence the seat belt use in real-life traffic in built-up areas in some European cities. The data were collected by field observations in major cities in six European countries and in five cities around Sweden. A selection of car models having seat belt reminders (SBR) were compared to a fleet of similar car models without such reminders. A significant difference in seat belt wearing rate was found in the cars with seat belt reminders. For all observations, the total seat belt wearing rate was 97.5% +/- 0.5% in cars with SBR, while it was 85.8% +/- 0.8% in cars without. There were differences in seat belt use in the different observation locations. The lowest seat belt use was found in Brussels/Belgium with a use rate of 92.6 +/- 2.2% in cars with seat belt reminders and 69.6 +/- 3.1% in cars not fitted with reminders. The highest seat belt use was found in Paris/France where 99.8 +/- 0.4% of the drivers used the seat belt in cars with reminders and 96.9 +/-1.1% were belted in cars without reminders. Seat belt reminders fulfilling Euro NCAP's seat belt reminder protocol are increasing the seat belt use in daily traffic significantly. Around 80% (82.2% +/- 8.6%) of the drivers not putting the belt on without a seat belt reminder do so in cars equipped with an SBR that has a light signal and an associated loud and clear sound signal.

  6. Geologic evolution of the Serrinha nucleus granite–greenstone terrane (NE Bahia, Brazil) constrained by U–Pb single zircon geochronology

    OpenAIRE

    Rios, Débora Correia; Davis, Donald Wayne; Conceicão, Herbet; Davis, W.J.; Rosa, Maria De Lourdes Da Silva; Dickin, A.P.

    2009-01-01

    p. 175–201 U–Pb single zircon crystallization ages were determined using TIMS and sensitive high resolution ion microprobe (SHRIMP) on samples of granitoid rocks exposed in the Serrinha nucleus granite–greenstone terrane, in NE Brazil. Our data show that the granitoid plutons can be divided into three distinct groups. Group 1 consists of Mesoarchaean (3.2–2.9 Ga) gneisses and N-S elongated TTG (Tonalite-Trondhjemite-Granodiorite) plutons with gneissic borders. Group 2 is represented by ca....

  7. 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.

  8. 1962 Satellite High Altitude Radiation Belt Database

    Science.gov (United States)

    2014-03-01

    TR-14-18 1962 Satellite High Altitude Radiation Belt Database Approved for public release; distribution is unlimited. March...the Status of the High Altitude Nuclear Explosion (HANE) Trapped Radiation Belt Database”, AFRL-VS-PS-TR- 2006-1079, Air Force Research Laboratory...Roth, B., “Blue Ribbon Panel and Support Work Assessing the Status of the High Altitude Nuclear Explosion (HANE) Trapped Radiation Belt Database

  9. Cooling age of the Birimian juvenile crust in West Africa. U-Pb, Rb-Sr and K-Ar data on the 2. 1 Ga granite-greenstone terrains from SW-Niger. Age de refroidissement de la croute juvenile birimienne d'Afrique de l'Ouest. Donnees U-Pb, Rb-Sr et K-Ar sur les formations a 2. 1 Ga du SW-Niger

    Energy Technology Data Exchange (ETDEWEB)

    Lama, C.; Dautel, D.; Zimmermann, J.L. (Centre National de la Recherche Scientifique (CNRS), 54 - Nancy (France). Centre de Recherches Petrographiques et Geochimiques); Barbey, P. (Nancy-1 Univ., 54 (France)); Cheilletz, A. (Centre National de la Recherche Scientifique (CNRS), 54 - Nancy (France). Centre de Recherches Petrographiques et Geochimiques Ecole Nationale Superieure de Geologie Appliquee et de Prospection Miniere, 54 - Nancy (France)); Pons, J. (Orleans Univ., 45 (France))

    1994-08-18

    A comparison between zircon U-Pb, whole-rock Rb-Sr and biotite-amphibole K-Ar data on Birimian granite-greenstone terrains from SW-Niger indicates that the youngest granitic plutons were emplaced at 2.115 [+-] 5 Ma and that both the plutons and the surrounding greenstones yield cooling ages around 2.118 Ma. The age similarity between the end of the plutonism and the cooling of plutons and surrounding greenstone further suggests rapid cooling at the end of the plutonic event and, thus, corroborates a model of greenstone metamorphism linked to the thermal effect of the plutons. (authors).

  10. Crustal evolution and metallogeny in relation to mantle dynamics: A perspective from P-wave tomography of the South China Block

    Science.gov (United States)

    He, Chuansong; Santosh, M.

    2016-10-01

    The South China Block, composed of the Yangtze and Cathaysia sub-blocks which were sutured along the Jiangnan Orogen, preserves the records of multiple tectonothermal and metallogenic events coeval with global supercontinental cycles. In this study, we attempt to evaluate the mantle dynamics in this region based on P-wave tomographic analyses from data recorded by the China seismic network from 2007 to 2014. Our study reveals significant velocity perturbations in the upper mantle and mantle transition zone beneath this region which we correlate with various features including remnant and stagnant slabs resulting from Neoproterozoic subduction events and prominent mantle upwellings. Four vertical cross-sections along the latitudinal profiles indicate significant low velocity perturbation located at the mantle transition zone and upper mantle beneath the Cathaysia block and Jiangnan orogenic belt. South China is one of the major multi-metal provinces of the globe, and carries several large-scale ore deposits associated with a variety of tectonic settings. The distribution of major mineral deposits in the Yangtze and Cathaysia blocks as well as along the Jiangnan Orogen reveals a remarkable correlation between the location of the deposits and deep-seated low velocity P-wave anomalies. These features highlight the role of mantle dynamics and resultant crust mantle-interaction as well as crustal melting and recycling in generating the major metallogenic belts in this region.

  11. Formation of Kuiper Belt Binaries

    CERN Document Server

    Goldreich, P; Sari, R; Goldreich, Peter; Lithwick, Yoram; Sari, Re'em

    2002-01-01

    It appears that at least several percent of large Kuiper belt objects are members of wide binaries. Physical collisions are too infrequent to account for their formation. Collisionless gravitational interactions are more promising. These provide two channels for binary formation. In each, the initial step is the formation of a transient binary when two large bodies penetrate each other's Hill spheres. Stabilization of a transient binary requires that it lose energy. Either dynamical friction due to small bodies or the scattering of a third large body can be responsible. Our estimates favor the former, albeit by a small margin. We predict that most objects of size comparable to those currently observed in the Kuiper belt are members of multiple systems. More specifically, we derive the probability that a large body is a member of a binary with semi-major axis of order a. The probability depends upon sigma, the total surface density, Sigma, the surface density of large bodies having radius R, and theta=10^-4, t...

  12. Jupiter's radiation belts and atmosphere

    Science.gov (United States)

    De Pater, I.; Dames, H. A. C.

    1979-01-01

    Maps and stripscans of the radio emission from Jupiter were made during the Pioneer 10 flyby in December 1973 at wavelengths of 6 cm, 21 cm, and 50 cm using the Westerbork telescope in the Netherlands. With this instrument the disk of the planet was resolved at 6 and 21 cm. The pictures are averaged over 15 deg of Jovian longitude. At 21 cm the stripscans clearly show the existence of a 'hot region' in the radiation belts at a System III longitude (1965.0) of 255 + or - 10 deg. Its flux is about 9% of the total nonthermal flux, and it has a volume emissivity enhanced by a factor of about 1.6 with respect to the general radiation belts. The temperature of the thermal disk at 21 cm appears to be 290 + or - 20 K. This is likely due to a high ammonia mixing ratio in the atmosphere, a factor of 4-5 larger than the expected solar value of 0.00015.

  13. Beyond the Kuiper Belt Edge

    Science.gov (United States)

    Sheppard, Scott

    2013-01-01

    Of the thousands of known objects beyond Neptune, only one has a perihelion significantly beyond 50 AU, Sedna at 75 AU. Most Kuiper Belt surveys to date either did not go faint enough, did not have the required long cadence to detect very slow moving objects or covered too small of an area of sky to efficiently detect objects beyond 50 AU. The dynamical and physical properties of objects in this region offer key constraints on the formation and evolution of our solar system. In order to probe the Sedna like population of objects with moderate radii (100 km) we are conducting a deep wide-field outer solar system survey. This survey will allow us to determine if the objects beyond 50 AU are fainter than expected, if there is truly a dearth of objects, or if the Kuiper Belt continues again after some sizable gap possibly caused by a planet sized object. We will be able to examine the origin of Sedna and determine if it is unique (as once believed for Pluto) or one of a new class of object. We request one night in 2013B to recover a very interesting object that we discovered at Subaru in July 2012 and complete the sky coverage needed to constrain the Sedna-like population. This one night was awarded to us in 2012B but lost because of instrument problems.

  14. Southern Brasilia Belt (SE Brazil): tectonic discontinuities, K-Ar data and evolution during the Neoproterozoic Brasiliano orogeny

    Energy Technology Data Exchange (ETDEWEB)

    Valeriano, Claudio Morrison de [Universidade do Estado, Rio de Janeiro, RJ (Brazil)]. E-mail: cmval@uerj.br; Teixeira, Wilson [Sao Paulo Univ., SP (Brazil); Simoes, Luiz Sergio Amarante [UNESP, Sao Paulo, SP (Brazil); Heilbron, Monica [Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq), Brasilia, DF (Brazil)

    2000-03-01

    This paper focuses the tectonic evolution of the southern brasilia belt, with emphasis on the Furnas segment, along the 21 deg C S parallel. The uppermost structural unit (Passos Nappe - PN) comprises a highly deformed metasedimentary succession interpreted as a fragment of the Neoproterozoic passive margin of western Sao francisco craton. An inverted metamorphic gradient ranging from greensvhits to lower granulite facies of medium to high-pressure regime characterizes the PN as relict of a subduction zone. The External Domain display a complex imbrication of basement rocks (Archean Piumhi greenstones, a turbiditic gaywacke succession and a calc-alkaline granitoid suite) with undated siliciclast low-grade metasedimentary rocks. The Sao Francisco Craton (SFC) comprises pre-1.8 Ga basement rocks covered by anchimetamorphic Neoproterozoic carbonatic shallow marine platform deposits of the Bambui group. The Brasiliano thrust stacking generated a coarse clastic influx of molassic character on the foreland zone of Sao Francisco Craton, coeval with the exhumation of the External Domain thrust sheets. New K-Ar determinations on mineral separates are presented an interpreted among previous data. The SFC basement rocks display Paleo-to Meesoproterozoic cooling ages. The allochthonous units, in contrast, display K-Ar ages within the 560-675 Ma range. Brasiliano thrust stacking is therefore interpreted to have taken place onto a cold Sao Francisco craton foreland, in a thin-skinned style, as basement rocks were not heated enough to have their-K-ar systems reset during the allochthony. (author)

  15. Parameters affecting seat belt use in Greece.

    Science.gov (United States)

    Yannis, G; Laiou, A; Vardaki, S; Papadimitriou, E; Dragomanovits, A; Kanellaidis, G

    2011-09-01

    The objective of this research is the exploration of seat belt use in Greece and particularly the identification of the parameters affecting seat belt use in Greece. A national field survey was conducted for the analytical recording of seat belt use. A binary logistic regression model was developed, and the impact of each parameter on seat belt use in Greece was quantified. Parameters included in the model concern characteristics of car occupants (gender, age and position in the car), the type of the car and the type of the road network. The data collection revealed that in Greece, the non-use of seat belt on the urban road network was higher than on the national and rural road network and young and older men use seat belts the least. The developed model showed that travelling on a national road is negative for not wearing the seat belt. Finally, the variable with the highest impact on not wearing a seat belt is being a passenger on the back seats.

  16. Intelligent Belt Conveyor Monitoring and Control

    NARCIS (Netherlands)

    Pang, Y.

    2010-01-01

    Belt conveyors have been used worldwide in continuous material transport for about 250 years. Traditional inspection and monitoring of large-scale belt conveyors focus on individual critical components and response to catastrophic system failures. To prevent operational problems caused by the lack

  17. The Administrator's "Handy Dandy" Tool Belt

    Science.gov (United States)

    Anderson, Terry

    2012-01-01

    Every good leader needs a tool belt. Throughout the author's years of building early childhood programs, she has acquired a number of tools for her personal belt. These tools have helped her sharpen her skills in supporting teachers and staff, connecting with families, and educating children. This article focuses on those leadership skills that…

  18. Intelligent Belt Conveyor Monitoring and Control

    NARCIS (Netherlands)

    Pang, Y.

    2010-01-01

    Belt conveyors have been used worldwide in continuous material transport for about 250 years. Traditional inspection and monitoring of large-scale belt conveyors focus on individual critical components and response to catastrophic system failures. To prevent operational problems caused by the lack o

  19. Biomechanics of seat belt restraint system.

    Science.gov (United States)

    Sances, Anthony; Kumaresan, Srirangam; Herbst, Brian; Meyer, Steve; Hock, Davis

    2004-01-01

    Seat belt system restrains and protects occupants in motor vehicle crashes and any slack in seat belt system induces additional loading on occupant. Signs of belt loading are more obvious in high-speed frontal collisions with heavy occupants. However subtle changes may occur at low speeds or with low forces from occupants during rollovers. In certain cases, the seat belt webbing is twisted and loaded by the occupant. The loading of webbing induces an observable fold/crimp on the seat belt. The purpose of the study is to biomechanically evaluate the force required to produce such marks using an anthropometric physical test dummy. Two tests were conducted to determine the amount of force required to put an observable fold/crimp in a shoulder belt. A head form designed by Voight Hodgson was used to represent the neck which interacted with the belt. The force was applied with a pneumatic pull ram (central hydraulic 89182 N) and the force was measured with a 44,000 N transducer load cell (DSM-10K). Results indicate that the force of over 1,000 N produced a fold or crimp in the belt.

  20. Seat Belts on School Buses: Some Considerations.

    Science.gov (United States)

    Soule, David

    1982-01-01

    A representative of the National Highway Traffic Safety Administration weighs advantages and discusses issues associated with installing seat belts in school buses. Federal regulations and research findings are considered. A list of guideline questions for school districts planning to install seat belts is included. (PP)

  1. Seat belt use in cars with air bags.

    Science.gov (United States)

    Williams, A F; Wells, J K; Lund, A K

    1990-12-01

    Seat belt use was observed in 1,628 cars with air bags and manual belts and 34,223 cars with manual seat belts only. Sixty-six percent of drivers in cars with air bags wore seat belts compared to 63 percent of drivers in cars with manual belts only. The study found no evidence for the speculation that drivers with air bags will reduce their seat belt use because they believe an air bag alone provides sufficient protection.

  2. Radiation belt dynamics during solar minimum

    Energy Technology Data Exchange (ETDEWEB)

    Gussenhoven, M.S.; Mullen, E.G. (Geophysics Lab., Air Force Systems Command, Hanscom AFB, MA (US)); Holeman, E. (Physics Dept., Boston College, Chestnut Hill, MA (US))

    1989-12-01

    Two types of temporal variation in the radiation belts are studied using low altitude data taken onboard the DMSP F7 satellite: those associated with the solar cycle and those associated with large magnetic storm effects. Over a three-year period from 1984 to 1987 and encompassing solar minimum, the protons in the heart of the inner belt increased at a rate of approximately 6% per year. Over the same period, outer zone electron enhancements declined both in number and peak intensity. During the large magnetic storm of February 1986, following the period of peak ring current intensity, a second proton belt with energies up to 50 MeV was found at magnetic latitudes between 45{degrees} and 55{degrees}. The belt lasted for more than 100 days. The slot region between the inner and outer electron belts collapsed by the merging of the two populations and did not reform for 40 days.

  3. Seat belt use law in developing countries

    Institute of Scientific and Technical Information of China (English)

    SangWanLee

    1999-01-01

    Objective:To highlight the way to successful implementation of mandantory seat belt use law in developing countries particulary where have significant increase in number or cars and subsequent increase in car occupant casualties.Methods:Literatures concerning seat belt use were reviewed and experiences of the world.Satisfactory or not,investigated.It summed up general aspects of seat belt use as well as benefits,attitude toward legislation and measures to enhance the usage.Results:Seat belt use has been proven and stood time tested as the most effective means to protect car occupants from road crash injuries.It appears to be arduous to achieve the golal of seat belt use law in developing countries. but possible via strategies appropriately leading to legislation and promotion of the belt usage.Conclusions:It is prime necessity for the government authorities to recognize the importance of seat belt use.There needs an organizational structure composed of relevant professional from both private and government sectors which is able to carry out every steps toward successful legislation and implementation:education,publicity,enforcement,evaluation and dissemination of the law's benefits.

  4. Drive Alive: Teen Seat Belt Survey Program

    Directory of Open Access Journals (Sweden)

    Loftin, Laurel

    2010-08-01

    Full Text Available Objective: To increase teen seat belt use among drivers at a rural high school by implementing the Drive Alive Pilot Program (DAPP, a theory-driven intervention built on highway safety best practices.Methods: The first component of the program was 20 observational teen seat belt surveys conducted by volunteer students in a high school parking lot over a 38-month period before and after the month-long intervention. The survey results were published in the newspaper. The second component was the use of incentives, such as gift cards, to promote teen seat belt use. The third component involved disincentives, such as increased police patrol and school policies. The fourth component was a programmatic intervention that focused on education and media coverage of the DAPP program.Results: Eleven pre-intervention surveys and nine post-intervention surveys were conducted before and after the intervention. The pre- and post-intervention seat belt usage showed significant differences (p<0.0001. The average pre-intervention seat belt usage rate was 51.2%, while the average post-intervention rate was 74.5%. This represents a percentage point increase of 23.3 in seat belt use after the DAPP intervention.Conclusion: Based on seat belt observational surveys, the DAPP was effective in increasing seat belt use among rural high school teenagers. Utilizing a theory-based program that builds on existing best practices can increase the observed seat belt usage among rural high school students. [West J Emerg Med. 2010; 11(3: 280-283.

  5. Computer-aided design of conveyor belts

    Energy Technology Data Exchange (ETDEWEB)

    Karolewski, B.; Pytel, J.

    1984-01-01

    Possibilities are discussed for using mathematical models of belt conveyors for development of computer-aided design of conveyors for coal mining. Examples of optimization tasks and methods for their solution using computerized simulation are analyzed. The analysis is illustrated by an algorithm used to design a starter for the drive system of a belt conveyor. Electromagnetic moment and starting current are used as optimization criteria. A simplified model of a belt conveyor is used. The model consists of an equation of motion with variable braking moment and variable moment of inertia. 3 references.

  6. Collisional evolution of the early asteroid belt

    Science.gov (United States)

    Gil-Hutton, Ricardo; Brunini, Adrián

    1999-04-01

    We present numerical results obtained by a simulation of the collisional process between asteroids and scattered comets from the Uranus-Neptune zone. This mechanism allows the use of single exponent incremental size distributions for the initial belt reaching a final distribution that matches the observed population very well. Since the cometary bombardment was extremely efficient removing mass from the primordial asteroid belt in a very short time, we always obtained belts with total masses less than 0.001 M ⊕ after ≈ 2×10 7 yrs. This result allows processes with an important initial mass preserving Vestas basaltic crust.

  7. 30 CFR 56.14131 - Seat belts for haulage trucks.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Seat belts for haulage trucks. 56.14131 Section... Equipment Safety Devices and Maintenance Requirements § 56.14131 Seat belts for haulage trucks. (a) Seat belts shall be provided and worn in haulage trucks. (b) Seat belts shall be maintained in...

  8. Early Archaean sedimentary basins: depositional environment and hydrothermal systems. Geologica Ultraiectina (244)

    NARCIS (Netherlands)

    de Vries, S.T.|info:eu-repo/dai/nl/33656791X

    2004-01-01

    The topic of this thesis is the Early Archaean environment and hydrothermal systems in the Barberton Greenstone Belt (BGB) in South Africa, and the Coppin Gap Greenstone Belt (CGGB) in the Pilbara, Australia. Focus within these greenstone belts is on the ~3.45-3.42 Ga Buck Ridge volcano-sedimentary

  9. Early Archaean sedimentary basins: depositional environment and hydrothermal systems :

    NARCIS (Netherlands)

    Vries, Sjoukje Tsjitske de

    2004-01-01

    The topic of this thesis is the Early Archaean environment and hydrothermal systems in the Barberton Greenstone Belt (BGB) in South Africa, and the Coppin Gap Greenstone Belt (CGGB) in the Pilbara, Australia. Focus within these greenstone belts is on the ~3.45-3.42 Ga Buck Ridge volcano-sedimentary

  10. Simulation of engine auxiliary drive V-belt slip motion. Part 1. Development of belt slip model; Engine hoki V belt slip kyodo no simulation. 1. Belt slip model no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Kurisu, T. [Mazda Motor Corp., Hiroshima (Japan)

    1997-10-01

    V-belts are widely used for driving auxiliary components of an engine. Inadequet design of such belt system sometimes results in troubles such as belt squeak, side rubber separation and/or bottom rubber crack. However, there has been no design tools which can predict belt slip quantitatively. The author developed a motion simulation program of Auxiliary Drive V-Belt System considering belt slip. The program showed good prediction accuracy for belt slip motion. This paper describes the simulation model. 1 ref., 12 figs.

  11. Seat Belt Usage on School Buses.

    Science.gov (United States)

    Farmer, Ernest

    1985-01-01

    Studies on seat belt usage conducted under contract with governmental organizations or prepared by professional societies, state and local organizations, and transportation specialists have made significant contributions, but none has successfully resolved the issue. (MLF)

  12. Handbook Timing Belts Principles, Calculations, Applications

    CERN Document Server

    Perneder, Raimund

    2012-01-01

    Timing belts offer a broad range of innovative drivetrain solutions; they allow low-backlash operation in robot systems, they are widely used in automated processes and industrial handling involving highly dynamic start-up loads, they are low-maintenance solutions for continuous operation applications, and they can guarantee exact positioning at high operating speeds. Based on his years of professional experience, the author has developed concise guidelines for the dimensioning of timing belt drives and presents proven examples from the fields of power transmission, transport and linear transfer technology. He offers definitive support for dealing with and compensating for adverse operating conditions and belt damage, as well as advice on drive optimization and guidelines for the design of drivetrain details and supporting systems. All market-standard timing belts are listed as brand neutral. Readers will discover an extensive bibliography with information on the various manufacturers and their websites. This...

  13. Radiation Belt Storm Probe (RBSP) Mission

    Science.gov (United States)

    Sibeck, D. G.; Fox, N.; Grebowsky, J. M.; Mauk, B. H.

    2009-01-01

    Scheduled to launch in May 2012, NASA's dual spacecraft Living With a Star Radiation Belt Storm Probe mission carries the field and particle instrumentation needed to determine the processes that produce enhancements in radiation belt ion and electron fluxes, the dominant mechanisms that cause the loss of relativistic electrons, and the manner by which the ring current and other geomagnetic phenomena affect radiation belt behavior. The two spacecraft will operate in low-inclination elliptical lapping orbits around the Earth, within and immediately exterior to the Van Allen radiation belts. During course of their two year primary mission, they will cover the full range of local times, measuring both AC and DC electric and magnetic fields to 10kHz, as well as ions from 50 eV to 1 GeV and electrons with energies ranging from 50 eV to 10 MeV.

  14. Radiation Belt and Plasma Model Requirements

    Science.gov (United States)

    Barth, Janet L.

    2005-01-01

    Contents include the following: Radiation belt and plasma model environment. Environment hazards for systems and humans. Need for new models. How models are used. Model requirements. How can space weather community help?

  15. The Compositional Structure of the Asteroid Belt

    CERN Document Server

    DeMeo, Francesca E; Walsh, Kevin J; Chapman, Clark R; Binzel, Richard P

    2015-01-01

    The past decade has brought major improvements in large-scale asteroid discovery and characterization with over half a million known asteroids and over 100,000 with some measurement of physical characterization. This explosion of data has allowed us to create a new global picture of the Main Asteroid Belt. Put in context with meteorite measurements and dynamical models, a new and more complete picture of Solar System evolution has emerged. The question has changed from "What was the original compositional gradient of the Asteroid Belt?" to "What was the original compositional gradient of small bodies across the entire Solar System?" No longer is the leading theory that two belts of planetesimals are primordial, but instead those belts were formed and sculpted through evolutionary processes after Solar System formation. This article reviews the advancements on the fronts of asteroid compositional characterization, meteorite measurements, and dynamical theories in the context of the heliocentric distribution of...

  16. Eccentricity distribution in the main asteroid belt

    CERN Document Server

    Malhotra, Renu

    2016-01-01

    The observationally complete sample of the main belt asteroids now spans more than two orders of magnitude in size and numbers more than 64,000 (excluding collisional family members). We undertook an analysis of asteroids' eccentricities and their interpretation with simple physical models. We find that Plummer's (1916) conclusion that the asteroids' eccentricities follow a Rayleigh distribution holds for the osculating eccentricities of large asteroids, but the proper eccentricities deviate from a Rayleigh distribution: there is a deficit of eccentricities smaller than $\\sim0.1$ and an excess of larger eccentricities. We further find that the proper eccentricities do not depend significantly on asteroid size but have strong dependence on heliocentric distance: the outer asteroid belt follows a Rayleigh distribution, but the inner belt is strikingly different. Eccentricities in the inner belt can be modeled as a vector sum of a primordial eccentricity vector of random orientation and magnitude drawn from a Ra...

  17. Drive Alive: Teen Seat Belt Survey Program

    OpenAIRE

    Burkett, Katie M.; Davidson, Steve; Cotton, Carol; Barlament, James; Loftin, Laurel; Stephens, James; Dunbar, Martin; Butterfield, Ryan

    2010-01-01

    Objective: To increase teen seat belt use among drivers at a rural high school by implementing the Drive Alive Pilot Program (DAPP), a theory-driven intervention built on highway safety best practices. Methods: The first component of the program was 20 observational teen seat belt surveys conducted by volunteer students in a high school parking lot over a 38-month period before and after the month-long intervention. The survey results were published in the newspaper. The second compo...

  18. Jupiter's Radiation Belts: Can Pioneer 10 Survive?

    Science.gov (United States)

    Hess, W N; Birmingham, T J; Mead, G D

    1973-12-07

    Model calculations of Jupiter's electron and proton radiation belts indicate that the Galilean satellites can reduce particle fluxes in certain regions of the inner magnetosphere by as much as six orders of magnitude. Average fluxes should be reduced by a factor of 100 or more along the Pioneer 10 trajectory through the heart of Jupiter's radiation belts in early December. This may be enough to prevent serious radiation damage to the spacecraft.

  19. Seat-belt message and the law?

    Science.gov (United States)

    Sengupta, S K; Patil, N G; Law, G

    1989-09-01

    This paper attempts to draw together available information on the use of seat belts, one of the most important safety devices for a person in a car. Considering the high rate of mortality and morbidity due to road traffic accidents in Papua New Guinea the authors strongly feel that seat-belt usage should be made compulsory. When one looks at the history of the implementation of such a successful countermeasure in other countries it seems that legislation is the only answer.

  20. Eccentricity distribution in the main asteroid belt

    Science.gov (United States)

    Malhotra, Renu; Wang, Xianyu

    2017-03-01

    The observationally complete sample of the main belt asteroids now spans more than two orders of magnitude in size and numbers more than 64 000 (excluding collisional family members). We undertook an analysis of asteroids' eccentricities and their interpretation with simple physical models. We find that a century old conclusion that the asteroids' eccentricities follow a Rayleigh distribution holds for the osculating eccentricities of large asteroids, but the proper eccentricities deviate from a Rayleigh distribution; there is a deficit of eccentricities smaller than ∼0.1 and an excess of larger eccentricities. We further find that the proper eccentricities do not depend significantly on asteroid size but have strong dependence on heliocentric distance; the outer asteroid belt follows a Rayleigh distribution, but the inner belt is strikingly different. Eccentricities in the inner belt can be modelled as a vector sum of a primordial eccentricity vector of random orientation and magnitude drawn from a Rayleigh distribution of parameter ∼0.06, and an excitation of random phase and magnitude ∼0.13. These results imply that when a late dynamical excitation of the asteroids occurred, it was independent of asteroid size and was stronger in the inner belt than in the outer belt. We discuss implications for the primordial asteroid belt and suggest that the observationally complete sample size of main belt asteroids is large enough that more sophisticated model-fitting of the eccentricities is warranted and could serve to test alternative theoretical models of the dynamical excitation history of asteroids and its links to the migration history of the giant planets.

  1. Jupiter's magnetosphere and radiation belts

    Science.gov (United States)

    Kennel, C. F.; Coroniti, F. V.

    1979-01-01

    Radioastronomy and Pioneer data reveal the Jovian magnetosphere as a rotating magnetized source of relativistic particles and radio emission, comparable to astrophysical cosmic ray and radio sources, such as pulsars. According to Pioneer data, the magnetic field in the outer magnetosphere is radially extended into a highly time variable disk-shaped configuration which differs fundamentally from the earth's magnetosphere. The outer disk region, and the energetic particles confined in it, are modulated by Jupiter's 10 hr rotation period. The entire outer magnetosphere appears to change drastically on time scales of a few days to a week. In addition to its known modulation of the Jovian decametric radio bursts, Io was found to absorb some radiation belt particles and to accelerate others, and most importantly, to be a source of neutral atoms, and by inference, a heavy ion plasma which may significantly affect the hydrodynamic flow in the magnetosphere. Another important Pioneer finding is that the Jovian outer magnetosphere generates, or permits to escape, fluxes of relativistic electrons of such intensities that Jupiter may be regarded as the dominant source of 1 to 30 MeV cosmic ray electrons in the heliosphere.

  2. THE GOULD'S BELT DISTANCE SURVEY

    Directory of Open Access Journals (Sweden)

    L. Loinard

    2011-01-01

    Full Text Available Observaciones que utilizan la interferometría de muy larga línea de base (VLBI por sus siglas en ingl´es pueden proveer la posición de radiofuentes compactas con una precisión del orden de 50 micro-segundos de arco. Esto es suficiente para medir la paralaje trigonométrica y los movimientos propios de cualquier objeto localizado hasta 500 pc del Sol con una precisión mejor que unos porcientos. Por ser magnéticamente activas, las estrellas jóvenes a menudo emiten emisión radio compacta detectable usando técnicas VLBI. Aquí, mostraremos cómo observaciones VLBI ya han restringido la distancia a las regiones de formación estelar cercanas más frecuentemente estudiadas (Tauro, Ofiuco, Orión, etc. y han empezado a revelar su estructura y su cinemática interna. Luego, describiremos un gran proyecto (llamado The Gould's Belt Distance Survey diseñado para proveer una vista detallada de la formación estelar en la vecindad Solar, usando observaciones VLBI.

  3. Decay rate of the second radiation belt.

    Science.gov (United States)

    Badhwar, G D; Robbins, D E

    1996-01-01

    Variations in the Earth's trapped (Van Allen) belts produced by solar flare particle events are not well understood. Few observations of increases in particle populations have been reported. This is particularly true for effects in low Earth orbit, where manned spaceflights are conducted. This paper reports the existence of a second proton belt and it's subsequent decay as measured by a tissue-equivalent proportional counter and a particle spectrometer on five Space Shuttle flights covering an eighteen-month period. The creation of this second belt is attributed to the injection of particles from a solar particle event which occurred at 2246 UT, March 22, 1991. Comparisons with observations onboard the Russian Mir space station and other unmanned satellites are made. Shuttle measurements and data from other spacecraft are used to determine that the e-folding time of the peak of the second proton belt. It was ten months. Proton populations in the second belt returned to values of quiescent times within eighteen months. The increase in absorbed dose attributed to protons in the second belt was approximately 20%. Passive dosimeter measurements were in good agreement with this value.

  4. Geochemical Evidence for Subduction in the Early Archaean from Quartz-Carbonate-Fuchsite Mineralization, Isua Supracrustal Belt, West Greenland

    Science.gov (United States)

    Pope, E. C.; Rosing, M. T.; Bird, D. K.

    2011-12-01

    Quartz, carbonate and fuchsite (chromian muscovite) is a common metasomatic assemblage observed in orogenic gold systems, both in Phanerozoic convergent margin settings, and within supracrustal and greenstone belts of Precambrian rocks. Geologic and geochemical observations in younger orogenic systems suggest that ore-forming metasomatic fluids are derived from subduction-related devolitilization reactions, implying that orogenic Au-deposits in Archaean and Proterozoic supracrustal rock suites are related to subduction-style plate tectonics beginning early in Earth history. Justification of this metasomatic-tectonic relationship requires that 1) Phanerozoic orogenic Au-deposits form in subduction-zone environments, and 2) the geochemical similarity of Precambrian orogenic deposits to their younger counterparts is the result of having the same petro-genetic origin. Hydrogen and oxygen isotope compositions of fuchsite and quartz from auriferous mineralization in the ca. 3.8 Ga Isua Supracrustal Belt (ISB) in West Greenland, in conjunction with elevated concentrations of CO2, Cr, Al, K and silica relative to protolith assemblages, suggest that this mineralization shares a common petro-tectonic origin with Phanerozoic orogenic deposits and that this type of metasomatism is a unique result of subduction-related processes. Fuchsite from the ISB has a δ18O and δD of +7.7 to +17.9% and -115 to -61%, respectively. δ18O of quartz from the same rocks is between +10.3 and +18.6%. Muscovite-quartz oxygen isotope thermometry indicates that the mineralization occurred at 560 ± 90oC, from fluids with a δD of -73 to -49% and δ18O of +8.8 to +17.2%. Calculation of isotopic fractionation during fluid-rock reactions along hypothetical fluid pathways demonstrates that these values, as well as those in younger orogenic deposits, are the result of seawater-derived fluids liberated from subducting lithosphere interacting with ultramafic rocks in the mantle wedge and lower crust

  5. Seat belts, airbags and child protection devices. [previously: Seat belts and child restraint seats.

    NARCIS (Netherlands)

    2010-01-01

    In the Netherlands, the use of seat belts results in a yearly reduction of hundreds of fatalities. Seat belts reduce the risk of fatal injury by 37 to 48%, depending on the position in the car. At 50%, the effect of child protection devices is even slightly higher. When last measured (in 2010), 97%

  6. Flat belt continuously variable high speed drive

    Energy Technology Data Exchange (ETDEWEB)

    Kumm, E.L.

    1992-02-01

    A study was undertaken at Kumm Industries funded by DOE in the NBS/DOE Energy-Related Inventions Program starting in August 1990 to design, construct and test a novel very high speed flat belt drive. The test arrangement as shown in Figure 1 consists of a multiple belt-pulley configuration that transmits power from a low speed (2000--4000 RPM) input to a small pulley turbine'' (27,000 to 55,000 RPM) and then to the low speed output variable radius pulley (2000--5000 RPM) via a special self-active tensioner. Transmitting 25 HP to and from the turbine'' corresponds to obtaining 50 HP in one direction only in a possible turbo compounded engine application. The high speed of the turbine'' belts, i.e. 100 meters/sec. at 55,000 RPM, while transferring substantial power is a new much higher operating regime for belts. The study showed that the available belts gave overall test rig efficiencies somewhat above 80% for the higher speeds (50,000 RPM) and higher powers (corresponding to above 90% in the turbocompound application) and a significantly better efficiencies at slightly lower speeds. The tests revealed a number of improved approaches in the design of such high speed drives. It appears that there is considerable possibility for further improvement and application of such equipment.

  7. The effects of Maine's change to primary seat belt law on seat belt use and public perception and awareness.

    Science.gov (United States)

    Chaudhary, Neil K; Tison, Julie; Casanova, Tara

    2010-04-01

    Maine upgraded its seat belt law to primary enforcement on September 20, 2007. Belt observations during the day and night were conducted along with awareness surveys in state licensing offices. Both daytime and nighttime observed belt use increased in the months following implementation of the law (daytime 77-84%; night 69-81%). Although daytime belt use was generally higher, nighttime belt use showed a greater increase than daytime belt use. Awareness surveys indicated that Maine motorists were clearly aware of the law change and its consequences. Survey respondents also indicated having heard both messages about enforcement and messages encouraging belt use. Primary seat belt laws may have a stronger effect on belt use at night--when risk is higher--than during the day.

  8. Friction and Wear in Timing Belt Drives

    Directory of Open Access Journals (Sweden)

    B. Stojanovic

    2010-09-01

    Full Text Available Timing belt tooth goes into contact with a drive pulley, stretched to the maximum, because of the previous tension. When the contact begins the peak of the belt tooth makes the contact with the outer surface of the pulley teeth. The process of the teeth entering into the contact zone is accompanied with the relative sliding of their side surfaces and appropriate friction force. The normal force value is changing with the parabolic function, which also leads to the changes of the friction force. The biggest value of the normal force and of the friction force is at the tooth root. Hollow between teeth and the tip of the pulley teeth are also in contact. Occasionally, the face surface of the belt and the flange are also in contact. The friction occurs in those tribomechanical systems, also. Values of these friction forces are lower compared with the friction force, which occurs at the teeth root.

  9. Ionospheric heating for radiation-belt control

    Energy Technology Data Exchange (ETDEWEB)

    Burke, W.J.; Villalon, E.

    1990-10-01

    Pitch-angle scattering interactions of electromagnetic waves in the ELF/VLF bands with trapped electrons, as formulated by Kennel and Petschek 1, describe the dynamics of the freshly filled radiation belts flux tubes. The natural existence of a slot region with electron fluxes below the Kennel-Petschek limit requires non-local wave sources. We describe a set of planned, active experiments in which VLF radiation will be injected from ground and space based transmitters in conjunction with the CRRES satellite in the radiation belts. These experiments will measure the intensity of waves driving pitch-angle diffusion and the electron energies in gyroresonance with the waves. An ability to reduce the flux of energetic particles trapped in the radiation belts by artificial means could improve the reliability of microelectronic components on earth-observing satellites in middle-altitude orbits.

  10. Phlogopite compositions as an indicator of both the geodynamic context of granitoids and the metallogeny aspect in Memve'ele Archean area, northwestern Congo craton

    Science.gov (United States)

    Ntomba, Sylvestre M.; Bidzang, François Ndong; Ottou, José Eric Messi; Goussi Ngalamo, François Jeannot; Bisso, Dieudonné; Magnekou Takamte, Christelle Rufine; Ondoa, Joseph Mvondo

    2016-06-01

    A barium bearing phlogopite (celsian) has been found for the first time within the charnockitic and tonalitic suites that compose Archean mineral belt in Cameroon. Electron microprobe analyses of these phlogopites are reported and contain moderate contents of BaO (0.42-1.26 wt. %) and up to 5.95 wt. % TiO2. Micas are Mg-rich and their compositions indicate phlogopites rich-meroxenes. Phlogopites from Memve'ele are characterized by a nearly horizontal trend of increasing total aluminium (2.494-2.931 a.p.f.u.) and relatively constant Fe/(Fe + Mg) suggesting contributions of aluminous supracrustal material to the magmas by anatexis or assimilation. Compositions of the barium titanium bearing phlogopite vary systematically according to rock types. It seems that the substitution scheme include Ba + Al + VI (Mg, Fe)2+ + 2 IVSi = K + Si + VITi + 2IVAl was dominant in the Memve'ele area thus, this scheme has made easy incorporation of Ba into phlogopite structure. The binary diagram of aluminium vs. titanium shows that phlogopites from the Memve'ele area have been formed by the same metasomatic mechanism as phlogopites from Canary Island xenoliths and Mezitler andesites but Ba enrichment of phlogopites from the Memve'ele area implies an early Ba-metasomatism contrary to those from Mezitler. The estimated temperature of the studied phlogopites indicated mainly two groups: (1) temperature range from 662 to 688 °C (average 676 °C) for phlogopite grains with High Mg# in the trondhjemite sample and (2) temperatures with interval limits from 757 to 800 °C (average 777.07 °C) for remnant phlogopites; reflecting primary and late crystallization respectively from slightly to highly oxidized magma (-17.30 to -13.87 Kbars). The geothermal gradient with average temperatures are 35.57-53.360 °C/Km and 30.95-46.42 °C/Km corresponding to 14.56-21.84 Km and 14.56-30.58 Km depth of below crust respectively. The crystallizing melt is enriched in Ba emanated from sea water at medium

  11. Drive Alive: Teen Seat Belt Survey Program

    OpenAIRE

    Loftin, Laurel; Barlament, James; Cotton, Carol; Davidson, Steve M; Burkett, Katie M.; Stephens, James

    2010-01-01

    Objective: To increase teen seat belt use among drivers at a rural high school by implementing the Drive Alive Pilot Program (DAPP), a theory-driven intervention built on highway safety best practices.Methods: The first component of the program was 20 observational teen seat belt surveys conducted by volunteer students in a high school parking lot over a 38-month period before and after the month-long intervention. The survey results were published in the newspaper. The second component was t...

  12. Development of belt conveyor driving system

    Institute of Scientific and Technical Information of China (English)

    FU Jun-qing(付峻青); WANG Cong(王聪); HUO Wei(霍伟)

    2004-01-01

    A short review for the existing various driving methods for belt conveyor was given, which include the analysis and comparison about the advantages, disadvantages and suitable application range of these methods. Based on this the variable-frequency-control(VFC) method for belt conveyor drive was fully discussed with focus on its application in medium-high voltage range. The principle of Neutral Point Clamped (NPC) Three-Level Inverter using high-voltage IGBTs together with the control strategy of rotor field-oriented vector control for induction motor drive were illustrated.

  13. The radiation belt of the Sun

    CERN Document Server

    Gruzinov, Andrei

    2013-01-01

    For a given solar magnetic field, the near-Sun (phase-space) density of cosmic ray electrons and positrons of energy above about 10GeV can be calculated from first principles, without any assumptions about the cosmic ray diffusion. This is because the sunlight Compton drag must be more important than diffusion. If the solar magnetic field has an appreciable dipole component, the electron/positron density should have a belt-like dent, perhaps extending to several solar radii. The belt structure appears because the quasi-bound orbits are depopulated by the sunlight Compton drag.

  14. Composite Microdiscs with a Magnetic Belt

    DEFF Research Database (Denmark)

    Knaapila, Matti; Høyer, Henrik; Helgesen, Geir

    2015-01-01

    We describe an emulsion-based preparation of patchy composite particles (diameter of 100-500 mu m) consisting of a disclike epoxy core and a belt of porous polystyrene particles (diameter of 30 mu m) with magnetite within the pores. Compared to the magnetically uniform polystyrene particles......, the spontaneous aggregation of composite particles is suppressed when dispersed into liquid, which is attributed to the increased particle size, reduced magnetic susceptibility, and the shape of the magnetic domain distribution within the particles (spherical versus a belt). When the composite particles...

  15. Ionospheric heating for radiation belt control

    Science.gov (United States)

    Burke, William J.; Villalon, Elena

    1990-10-01

    Pitch-angle scattering interactions of electromagnetic waves in the ELF/VLF bands with trapped electrons describe the dynamics of the freshly filled radiation belts flux tubes. The natural existence of a 'slot' region with electron fluxes below the Kennel-Petschek limit requires non-local wave sources. A set of planned, active experiments is described in which VLF radiation is injected from ground and space band transmitters in conjunction with the Combined Release and Radiation Effects Satellite in the radiation belts. These experiments can measure the intensity if waves driving pitch-angle diffusion and the electron energies in gyroresonance with the waves.

  16. CALCULATION OF TENSION FORCE OF BELT CONVEYOR

    Directory of Open Access Journals (Sweden)

    Ismet Ibishi

    2012-12-01

    Full Text Available In this paper is done the explanation on tension fashion of the belt conveyor which is employed in Kosovo Energy Corporation – KEK, for coal transportation to provide electric power plant. The aim of the paper enables to recognize tension forces not to pass with deformation of belt so that this problem will damage the workingprocess. Work principle is based on initial tension and tension during working process. The fact is known that the tension starts from the carriage on the way to tension mechanization, so forces on the rope passing through pulley there has to dominate the friction coefficient. All this process is related to economy of transportationmechanism.

  17. 30 CFR 56.15020 - Life jackets and belts.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Life jackets and belts. 56.15020 Section 56.15020 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL... § 56.15020 Life jackets and belts. Life jackets or belts shall be worn where there is danger from...

  18. 30 CFR 57.15020 - Life jackets and belts.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Life jackets and belts. 57.15020 Section 57.15020 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL... Protection Surface Only § 57.15020 Life jackets and belts. Life jackets or belts shall be worn where there is...

  19. 14 CFR 125.211 - Seat and safety belts.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Seat and safety belts. 125.211 Section 125... Requirements § 125.211 Seat and safety belts. (a) No person may operate an airplane unless there are available... share one approved safety belt and two persons occupying a multiple lounge or divan seat may share...

  20. 49 CFR 392.16 - Use of seat belts.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Use of seat belts. 392.16 Section 392.16... VEHICLES Driving of Commercial Motor Vehicles § 392.16 Use of seat belts. A commercial motor vehicle which has a seat belt assembly installed at the driver's seat shall not be driven unless the driver...

  1. Observed seat belt use in Kumasi Metropolis, Ghana.

    Science.gov (United States)

    Afukaar, Francis K; Damsere-Derry, James; Ackaah, Williams

    2010-01-01

    We conducted an observational survey of seat belt use to determine the use rate of drivers and front-right passengers of vehicles in Kumasi, Ghana. Unobtrusive observations of seat belt use were made at 41 locations composed of signalized intersections and roundabouts where vehicles come to a halt or slow down considerably. The overall driver seat belt use rate was 17.6% compared to 4.9% for front-right passengers. Driver belt use was 33.2% for private cars, 9.0% for taxis, 8.3% for minibus (trotro), 13.1% for large buses and 9.7% for trucks. Overall seat belt use was higher for female drivers than for male drivers (44.8% versus 16.4%, p seat belt use rate increased with age. Passengers belted more often if drivers were belted, but about three-quarters of male passengers and 70-80% of female passengers were unbelted even when drivers were belted. In conclusion, the seat belt use rate was generally low in Kumasi, Ghana, and it is a function of occupant seating position, gender, vehicle type and usage, age group, and location setting. The results provide important preliminary data about seat belt use, particularly among male drivers and commercial vehicle occupant population. The study also suggests the need to develop effective strategies and programs that address low seat belt use in Ghana.

  2. School Buses & Seat Belts: A Discussion.

    Science.gov (United States)

    Alaska State Dept. of Education, Juneau.

    Safety belts are not installed in school buses for several reasons. School buses are constructed differently from automobiles in terms of (1) the locations of doors and instrument panels relative to passengers, (2) outer construction, (3) seat design and padding, and (4) visibility on the road. Under current regulations, bus seats are constructed…

  3. Design aspects of multiple driven belt conveyors

    NARCIS (Netherlands)

    Nuttall, A.J.G.

    2007-01-01

    Worldwide belt conveyors are used to transport a great variety of bulk solid materials. The desire to carry higher tonnages over longer distances and more diverse routes, while keeping exploitation costs as low as possible, has fuelled many technological advances. An interesting development in the r

  4. Design aspects of multiple driven belt conveyors

    NARCIS (Netherlands)

    Nuttall, A.J.G.

    2007-01-01

    Worldwide belt conveyors are used to transport a great variety of bulk solid materials. The desire to carry higher tonnages over longer distances and more diverse routes, while keeping exploitation costs as low as possible, has fuelled many technological advances. An interesting development in the

  5. Pregnancy: Should I Use a Seat Belt?

    Science.gov (United States)

    ... always wear your seat belt even if your car has air bags.Where should I sit if I’m a ... editorial staff Categories: Family Health, Pregnancy and ChildbirthTags: air bag, auto accident, automobile safety, car accident, car safety, fetal injury, patient ...

  6. The thrust belts of Western North America

    Energy Technology Data Exchange (ETDEWEB)

    Moulton, F.C.

    1993-08-01

    Most of the Basin and Range physiographic province of western North America is now believed to be part of the overthrust. The more obvious overthrust belt along the eastern edge of the Basin and Range Province is named the Sevier orogenic belt, where older rocks are observed thrust onto younger rocks. More detailed surface geological mapping, plus deep multiple-fold geophysical work and many oil and gas wildcat wells, have confirmed an east-vergent shortened and stacked sequence is present in many places in the Basin and Range. This western compressive deformed area in east central Nevada is now named the Elko orogenic belt by the U.S. Geological Survey. This older compressed Elko orogenic belt started forming approximately 250 m.y. ago when the North American plate started to move west as the Pangaea supercontinent started to fragment. The North American plate moved west under the sediments of the Miogeocline that were also moving west. Surface-formed highlands and oceanic island arcs on the west edge of the North American plate restricted the westward movement of the sediments in the Miogeocline, causing east-vergent ramp thrusts to form above the westward-moving North American plate. The flat, eastward-up-cutting thrust assemblages moved on the detachment surfaces.

  7. Belts and Chains. FOS: Fundamentals of Service.

    Science.gov (United States)

    John Deere Co., Moline, IL.

    This manual on belts and chain drives is one of a series of power mechanics texts and visual aids on theory, of operation, diagnosis, and repair of automotive and off-the-road agricultural and construction equipment. Materials provide basic information and illustrations for use by vocational students and teachers as well as shop servicemen and…

  8. Belts and Chains. FOS: Fundamentals of Service.

    Science.gov (United States)

    John Deere Co., Moline, IL.

    This manual on belts and chain drives is one of a series of power mechanics texts and visual aids on theory, of operation, diagnosis, and repair of automotive and off-the-road agricultural and construction equipment. Materials provide basic information and illustrations for use by vocational students and teachers as well as shop servicemen and…

  9. Economic Valuation of Green Belt: Focusing on the Conservation Value of Green Belt in Greater Seoul

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Joon Koo [Seoul National University, Seoul (Korea); Shin, Young Cheol [Daejin University, Pochon (Korea)

    2000-09-01

    The purpose of this paper is to measure the benefits of conservation of the green belt in the Greater Seoul area by CVM using dichotomous choice with a follow-up elicitation method. According to the government's plan, part of the green belt in the Greater Seoul area is to be freed from green belt designation. The mean willingness-to-pay(WTP) to conserve the green belt in the current state turns out to be about 7,430 won(95% confidence interval 6,220{approx}8,640 won) per household, which amounts to 308 billion won per year for entire population of Seoul. This WTP figure is found to be significantly influenced by level of education, sex, and the variables related to the perception and attitudes of respondents. (author). 26 refs., 3 tabs.

  10. Belt fires and mine escape problems

    Energy Technology Data Exchange (ETDEWEB)

    Kovac, J.G.; Lazzara, C.P. [Bureau of Mines, Pittsburgh, PA (United States); Kravitz, J.H.

    1996-12-31

    A conveyor belt fire in an underground coal mine is a serious threat to life and property. About 30% of the reportable underground coal mine fires from 1988 through 1992 occurred in belt entries. In one instance, a fire started in the drive area of a belt line, spread rapidly, and resulted in seating of the entire mine. Large-scale studies conducted by the U.S. Bureau of Mines in an aboveground fire gallery at Lake Lynn Laboratory clearly show the hazards of conveyor belt fires. Mine conveyor belt formulations which passed the current Federal acceptance test for fire-resistant betting were completely consumed by propagating fires or propagated flame, with flame spread rates ranging from 0.3 to 9 m/min. High downstream temperatures and large quantities of smoke and toxic gases, such as carbon monoxide, were generated as the belting burned. The smoke and gases can be spread by the mine`s ventilation system and can create significant problems for miners in the process of evacuation, such as reduction in visibility and incapacitation. In the aftermath of a belt fire, the atmosphere inside of the mine can become smoke filled or unbreathable, forcing miners to evacuate while wearing Self-Contained Self-Rescuers (SCSR`s), Sometimes there is confusion about how to regard the rated duration of an MSHA/NIOSH-approved 60-min. SCSR, especially when an SCSR is used in a way which takes it outside of the test conditions under which it was approved. As examples, for a mine escape that takes a miner from the deepest point of penetration in the mine to the surface: How long will a 60-min. SCSR actually last? and How many SCSR`s will a miner need? To answer these kinds of questions, in-mine data being gathered on escape times, distance and heart rates using miners escaping on foot and under oxygen. A model will be developed and validated which predicts how much oxygen is actually needed for a mine escape, and compares oxygen consumption bare faced versus wearing an SCSR.

  11. Imaging Jupiter Radiation Belts At Low Frequencies

    Science.gov (United States)

    Girard, J. N.; de Pater, I.; Zarka, P.; Santos-Costa, D.; Sault, R.; Hess, S.; Cecconi, B.; Fender, R.; Pewg, Lofar

    2014-04-01

    The ultra-relativistic electrons, trapped in the inner radiation belts of Jupiter, generates a strong synchrotron radio emission (historically known as the jovian decimeter radiation (DIM)) which is beamed, polarized (~20% linear, ~1% circular) and broadband. It has been extensively observed by radio telescopes/ probes and imaged by radio interferometers over a wide frequency spectrum (from >300 MHz up to 22 GHz). This extended emission presents two main emission peaks constantly located on both sides of the planet close to the magnetic plane. High latitude emissions were also regularly observed at particular frequencies, times and in particular observational configurations. This region of the magnetosphere is "frozen" due to the strong magnetic field (~4.2 G as the equator) and therefore is forced to rotate at the planetary period (T≈9h55m). Due to the tilt (~ 10o) between the spin axis of the planet and the magnetic axis (which can be seen as dipolar in first approximation), the belts and the associated radio emission wobble around the planet center. The analysis of the flux at different frequencies highlighted spatial, temporal and spectral variabilities which origins are now partly understood. The emission varies at different time scales (short-time variations of hours to long-term variation over decades) due to the combination of visibility effect (wobbling, beaming, position of the observer in the magnetic rotating reference frame) [1], [2] and intrinsic local variations (interaction between relativistic electrons and satellites/dust, delayed effect of the solar wind ram pressure, impacts events) [3], [4], [5]. A complete framework is necessary to fully understand the source, loss and transport processes of the electrons originating from outside the belt, migrating by inward diffusion and populating the inner region of the magnetosphere. Only a few and unresolved measurements were made below 300 MHz and the nonsystematic observation of this radio emission

  12. International survey of seat belt use exemptions.

    Science.gov (United States)

    Weiss, H; Sirin, H; Levine, J A; Sauber, E

    2006-08-01

    Substantial evidence of seatbelt efficacy has been shown by several studies, and it is widely recommended that motor vehicle occupants use properly fitted seat belts. However, some (but a heretofore unknown number of) countries with national seat belt laws permit various exemptions which may lower use rates. The aim of this study was to survey the variety of exemptions to national seat belt laws. This investigation relied on identifying respondents from national traffic safety agencies, other governmental and non-governmental organizations, Internet searches, personal contacts, and other sources. Questionnaires were deployed through a web based survey supplemented by email and postal versions. Responses were received from 30 countries of which 28 (93.7%) had a national seat belt law. About two thirds (63.7%) of the 28 national laws applied to both front and back seat passengers. The leading exemption types included vehicles made before a certain year (n = 13), antique vehicles (n = 12), military vehicles (n = 11), buses (n = 9), and emergency vehicles (n = 8). Most responding countries reported one or more specific categories of individuals as exempt including those with medical exemptions (n = 20), taxi drivers (n = 11), police (n = 9), emergency medical personnel (n = 8), physically disabled people (n = 6), and pregnant women (n = 6). Out of 26 responses to the question regarding current level of enforcement, 42.3% felt enforcement was "very good or good" and 57.7% characterized it as "fair or poor". This study represents one of the largest international traffic law surveys reported. Most national seatbelt laws offer perilous exemptions to a broad array of vehicle types and road user groups. These findings, coupled with concern over the level of enforcement in the majority of countries surveyed, suggest that international road safety efforts have a long way to go to improve coverage and enforcement of national seat belt laws.

  13. High-resolution quadruple sulfur isotope analyses of 3.2 Ga pyrite from the Barberton Greenstone Belt in South Africa reveal distinct environmental controls on sulfide isotopic arrays

    NARCIS (Netherlands)

    Roerdink, D.L.; Mason, P.R.D.; Whitehouse, M.J.; Reimer, T.

    2013-01-01

    Multiple sulfur isotopes in Paleoarchean pyrite record valuable information on atmospheric processes and emerging microbial activity in the early sulfur cycle. Here, we report quadruple sulfur isotope data (32S, 33S, 34S, 36S) analyzed by secondary ion mass spectrometry from pyrite in a 3.26–3.23 Ga

  14. Nd-Sr Isotopic Geochemistry and U-Pb Geochronology of the Fé Granitic Gneiss and Lajedo Granodiorite: Implications for Paleoproterozoic Evolution of the Mineiro Belt, Southern São Francisco Craton, Brazil

    Directory of Open Access Journals (Sweden)

    Wilson Teixeira

    2008-04-01

    Full Text Available The Fé granitic gneiss and Lajedo granodiorite belong to a voluminous felsic-mafic plutonism, tectonically linked toPaleoproterozoic magmatic evolution of the Mineiro Belt, southern portion of the São Francisco Craton, central-easternBrazil. The Fé pluton is located north of the Lenheiros shear zone and is intrusive with respect to the Rio das Mortesgreenstone belt and pyroxenite - gabbroic bodies, as indicated by xenoliths of gneiss and amphibolite, in the first case, andpyroxenite in the latter. The Lajedo granodiorite is located south of the Lenheiros shear zone and cuts the metamafic rocks ofthe Forro peridotite – pyroxenite and mafic and intermediate rocks of the Nazareno greenstone belt, as evidenced by xenolithsfrom the latter unit. The modal composition of the Fé granitic gneiss lies within the ranges of monzogranite and syenogranite.It is peraluminous and shows a large variation in K2O content, which implies a middle-K calc-alkaline to high-K calc-alkalinetendency. The Lajedo modal composition is consistent with granodioritic and tonalitic compositions. It indicates a predominantlyperaluminous composition and calc-alkaline character. The U-Pb zircon crystallization age of the Fé granitic gneiss is 2191± 9 Ma, whereas the Lajedo granodiorite yields 2208 ± 26 Ma. The Nd/Sr characteristics of the Fé and Lajedo plutons areconsistent with mixtures of enriched mantle (EMI-type, DMM and crustal components during magma genesis in a plutonicarc setting, while the low 87Sr/86Sri ratios point to contribution of mafic rock protoliths during magma genesis. This is also inaccordance with the characteristic xenoliths observed within the investigated plutons from the Nazareno and Rio das Mortesgreenstone belts. The Fé granitic gneiss and Lajedo granodiorite show tectonic characteristics which are comparable to thoseof nearby coeval plutons: Brito quartz-diorite (2221 ± 2 Ma, Brumado de Cima granodiorite (2219 ± 2 Ma, Brumado de

  15. China belting up or down? Seat belt wearing trends in Nanjing and Zhoushan.

    Science.gov (United States)

    Routley, Virginia; Ozanne-Smith, Joan; Li, Dan; Yu, Min; Wang, Jianyue; Zhang, Junhe; Tong, Zhendong; Wu, Ming; Wang, Peihua; Qin, Yu

    2008-11-01

    National seat belt wearing legislation became effective in China May 2004 and associated provincial and city regulations followed. Despite rapid motorisation seat belt studies in China have been scarce. Patterns and trends in urban seat belt wearing were observed for all driver, front and rear seating positions over the years 2005-2007 in two eastern cities Nanjing (Jiangsu Province) and Zhoushan (Zhejiang Province). There were 35,256 vehicles observed in Nanjing, 20,939 in Zhoushan and 95,933 occupants overall. Males dominated all seating positions, especially drivers. Seat belt wearing overall was significantly higher for drivers (49.9% Nanjing, 47.4% Zhoushan) than for front seat passengers (9.1% Nanjing, 1.0% Zhoushan) and virtually nonexistent for rear passengers (0.5% Nanjing, 0.2% Zhoushan). Generally levels declined significantly from year to year (drivers Nanjing 66.7%, 47.7%, 38.6%; Zhoushan 57.4%, 57.9%, 30.6%; front passengers Nanjing 19.2%, 6.6%, 3.2%). Zhoushan wearing did not initially decline, 2006 observations coinciding with anticipation of provincial regulations (July 2006). Observations revealed an absence of child restraints. Pretend wearing/belt tampering was observed almost exclusively in taxi drivers (14.2% of Nanjing taxi drivers, 11.3% of Zhoushan's). Awareness of and attitudes to urban seat belt laws should be investigated, appropriate countermeasures developed and enforcement reassessed.

  16. The Gould Belt, the de Vaucouleurs-Dolidze Belt, and the Orion Arm

    CERN Document Server

    Bobylev, V V

    2014-01-01

    Based on masers with measured trigonometric parallaxes, we have redetermined the spatial orientation parameters of the Local (Orion) arm. Using 23 sources (the Gould Belt objects were excluded), we have found that their spatial distribution can be approximated by a very narrow ellipsoid elongated in the direction L_1=77.1+/-2.9^o whose symmetry plane is inclined to the Galactic plane at an angle of 5.6+/-0.2^o. The longitude of the ascending node of the symmetry plane is l_\\Omega=70+/-3^o. A new estimate for the pitch angle of the Local spiral arm has been obtained by an independent method: i=12.9+/-2.9^o. Previously, a belt of young B stars, the de Vaucouleurs.Dolidze belt, was pointed out on the celestial sphere with parameters close to such an orientation. We have refined the spatial orientation parameters of this belt based on a homogeneous sample of protostars. The de Vaucouleurs.Dolidze belt can be identified with the Local arm, with the belt proper as a continuous band on the celestial sphere like the ...

  17. VERO cells harbor a poly-ADP-ribose belt partnering their epithelial adhesion belt

    Directory of Open Access Journals (Sweden)

    Laura Lafon-Hughes

    2014-10-01

    Full Text Available Poly-ADP-ribose (PAR is a polymer of up to 400 ADP-ribose units synthesized by poly-ADP-ribose-polymerases (PARPs and degraded by poly-ADP-ribose-glycohydrolase (PARG. Nuclear PAR modulates chromatin compaction, affecting nuclear functions (gene expression, DNA repair. Diverse defined PARP cytoplasmic allocation patterns contrast with the yet still imprecise PAR distribution and still unclear functions. Based on previous evidence from other models, we hypothesized that PAR could be present in epithelial cells where cadherin-based adherens junctions are linked with the actin cytoskeleton (constituting the adhesion belt. In the present work, we have examined through immunofluorescence and confocal microscopy, the subcellular localization of PAR in an epithelial monkey kidney cell line (VERO. PAR was distinguished colocalizing with actin and vinculin in the epithelial belt, a location that has not been previously reported. Actin filaments disruption with cytochalasin D was paralleled by PAR belt disruption. Conversely, PARP inhibitors 3-aminobenzamide, PJ34 or XAV 939, affected PAR belt synthesis, actin distribution, cell shape and adhesion. Extracellular calcium chelation displayed similar effects. Our results demonstrate the existence of PAR in a novel subcellular localization. An initial interpretation of all the available evidence points towards TNKS-1 as the most probable PAR belt architect, although TNKS-2 involvement cannot be discarded. Forthcoming research will test this hypothesis as well as explore the existence of the PAR belt in other epithelial cells and deepen into its functional implications.

  18. The Glória quartz-monzodiorite: isotopic and chemical evidence of arc-related magmatism in the central part of the Paleoproterozoic Mineiro belt, Minas Gerais State, Brazil

    Directory of Open Access Journals (Sweden)

    Ciro A. Ávila

    2006-09-01

    Full Text Available The Glória quartz-monzodiorite, one of the mafic plutons of the Paleoproterozoic Mineiro belt, is intrusive into banded gneisses, amphibolites, schists and phyllites of the Rio das Mortes greenstone belt, in the southern portion of the São Francisco Craton, State of Minas Gerais, Brazil. The Glória quartz-monzodiorite yields a SHRIMP U-Pb zircon age of 2188 ± 29 Ma, suggesting a tectonic relationship with the pre-collisional phase of the Mineiro belt. According to the Nd isotopic evidence (epsilonNd(T = -3.4; T DM = 2.68 Ga the original magmas was formed by a mixture among Archean crustal material and Paleoproterozoic juvenile magma. The Glória quartz-monzodiorite shows metaluminous and calc-alkaline tendency with intermediate K content, comparable to that of volcanic-arc rocks. The primary mineralogical assemblage was partly modified by metamorphism, dated between 2131-2121 Ma in nearby coeval plutons. Such metamorphism is significantly older than the reported metamorphic episodes of the Mineiro belt in the Quadrilátero Ferrífero region (2059-2041 Ma in the eastern portion of the study area. This evidence, together with chemical and isotopic data from other mafic and felsic plutons coeval with the Glória quartz-monzodiorite, indicate a tectonic and magmatic migration within the Mineiro belt from west to east.O Quartzo Monzodiorito Glória é um corpo plutônicomáfico associado à evolução Paleoproterozóica do Cinturão Mineiro. Este é intrusivo em gnaisses bandados, anfibolitos, xistos e filitos do Greenstone Belt Rio das Mortes, na porção sudeste do Cráton São Francisco, Estado de Minas Gerais, Brasil. Este corpo possui idade de cristalização SHRIMP (em zircão de 2188 ± 29 Ma, enquanto os isótopos de Nd (épsilonNd(T = -3,4; T DM = 2,68 Ga apontam que sua fonte magmática envolveumaterial juvenil paleoproterozóico contaminada por protólitos arqueanos. As rochas do Quartzo Monzodiorito Glória são metaluminosas, c

  19. Seat Belt Use Among Adult Workers - 21 States, 2013.

    Science.gov (United States)

    Boal, Winifred L; Li, Jia; Rodriguez-Acosta, Rosa L

    2016-06-17

    Roadway incidents involving motorized vehicles accounted for 24% of fatal occupational injuries in the United States during 2013 and were the leading cause of fatal injuries among workers.* In 2013, workers' compensation costs for serious, nonfatal injuries among work-related roadway incidents involving motorized land vehicles were estimated at $2.96 billion.(†) Seat belt use is a proven method to reduce injuries to motor vehicle occupants (1). Use of lap/shoulder seat belts reduces the risk for fatal injuries to front seat occupants of cars by 45% and the risk to light truck occupants by 60%.(§) To characterize seat belt use among adult workers by occupational group, CDC analyzed data from the 2013 Behavioral Risk Factor Surveillance System (BRFSS) and found that not always using a seat belt was significantly associated with occupational group after controlling for factors known to influence seat belt use. Occupational groups with the highest prevalences of not always using a seat belt included construction and extraction; farming, fishing, and forestry; and installation, maintenance, and repair. To increase seat belt use among persons currently employed, states can enact and enforce primary seat belt laws, employers can set and enforce safety policies requiring seat belt use by all vehicle occupants, and seat belt safety advocates can target interventions to workers in occupational groups with lower reported seat belt use.

  20. LOAD DISTRIBUTION ON DRUMS OF DOUBLE DRIVE BELT CONVEYOR

    Institute of Scientific and Technical Information of China (English)

    薛河; 苏清祖; 马胜利

    1999-01-01

    The double drum drive is widely used on the mine belt conveyor, which are divided the rigid connected double drums and separately driving double drums according to connected method of two drums. Because of the change of real work condition, the load distribution is changed on the two drive drums, which may produce a slippage between a drum and belt. Slippage may intensify the wear of the drum, and sometimes causing the fire of the belt. This restricts the development toward narrow belt, high velocity and large power of belt conveyor. In this paper, the factors affecting the load distribution of two drums of double drum belt conveyor are'systematically analyzed and some computing formulas derived, by these formulas, the actual load distribution onthe two drums of rigid connected or separately driving belt conveyor can be separately calculated. These formulas also can be as the theory base for adjusting the driving force of two drums.

  1. Persistence of Salmonella on egg conveyor belts is dependent on the belt type but not on the rdar morphotype.

    Science.gov (United States)

    Stocki, S L; Annett, C B; Sibley, C D; McLaws, M; Checkley, S L; Singh, N; Surette, M G; White, A P

    2007-11-01

    Commercial caged layer flocks in Alberta, Canada, are commonly monitored for Salmonella enterica serovar Enteritidis (SE) and S. enterica serovar Typhimurium (ST) by environmental sampling. In one recent case, a SE strain isolated from the egg conveyor belt was a source of persistent infection for the flock. This study was undertaken to examine Salmonella colonization on egg conveyor belts and to determine whether the rdar morphotype, a conserved physiology associated with aggregation and long-term survival, contributed to persistence. Four woven belts constructed of natural or nonnatural fibers and a 1-piece belt made of vinyl were tested with rdar-positive ST and SE strains and a rdar-negative ST DeltaagfD reference strain. The type of egg belt was the most important factor influencing Salmonella colonization and persistence. The vinyl belt, with the least surface area available for colonization, had the fewest Salmonella remaining after washing and disinfection, whereas the hemp-plastic belt, with the greatest surface area, had the most Salmonella remaining. Real-time gene expression indicated that the rdar morphotype was involved in colonizing the egg belt pieces; however, it was not essential for persistence. In addition, rdar-positive and rdar-negative strains were equally similarly to disinfection on the egg belt pieces. The results indicate that Salmonella can persist on a variety of egg belts by mechanisms other than the rdar morphotype, and that using egg conveyer belts with reduced surface area for bacterial colonization can lessen contamination problems.

  2. Ionic composition of the earth's radiation belts

    Science.gov (United States)

    Spjeldvik, W. N.

    1983-01-01

    Several different ion species have been positively identified in the earth's radiation belts. Besides protons, there are substantial fluxes of helium, carbon and oxygen ions, and there are measurable quantities of even heavier ions. European, American and Soviet space experimenters have reported ion composition measurements over wide ranges of energies: at tens of keV (ring-current energies) and below, and at hundreds of keV and above. There is still a gap in the energy coverage from several tens to several hundreds of keV where little observational data are available. In this review emphasis is placed on the radiation belt ionic structure above 100 keV. Both quiet time conditions and geomagnetic storm periods are considered, and comparison of the available space observations is made with theoretical analysis of geomagnetically trapped ion spatial, energy and charge state distributions.

  3. HP metamorphic belt of the western Alps

    Institute of Scientific and Technical Information of China (English)

    RobertoCompagnoni

    2003-01-01

    The understanding of the subduction-related processes benefited by the studies of the high-pressure (HP) meta-morphic rocks from the western Alps. The most stimu-lating information was obtained from the inner part of the western Alpine belt, where most tectonic units show an early Alpine eclogite-facies recrystallisation. This is especially true for the Austroalpine Sesia Zone and the Penninic Dora-Maira massif. From the Sesia zone,which consists of a wide spectrum of continental crust lithologies recrystallised to quartz-eclogite-facies min-eral assemblages, the first finding of a jadeite-bearingmeta-granitoid has been described, supporting evidencethat even continental crust may subduct into the mantle.From the Dora-Maira massif the first occurrence of regional metamorphic coesite has been reported, open-ing the new fertile field of the ultrahigh-pressure meta-morphism (UHPM), which is now becoming the rule in the collisional orogenic belts.

  4. Alien Asteroid Belt Compared to our Own

    Science.gov (United States)

    2005-01-01

    [figure removed for brevity, see original site] Figure 1: Band of Light Comparison This artist's concept illustrates what the night sky might look like from a hypothetical alien planet in a star system with an asteroid belt 25 times as massive as the one in our own solar system (alien system above, ours below; see Figure 1). NASA's Spitzer Space Telescope found evidence for such a belt around the nearby star called HD 69830, when its infrared eyes spotted dust, presumably from asteroids banging together. The telescope did not find any evidence for a planet in the system, but astronomers speculate one or more may be present. The movie begins at dusk on the imaginary world, when HD 69830, like our Sun, has begun to set over the horizon. Time is sped up to show the onset of night and the appearance of a brilliant band of light. This light comes from dust in a massive asteroid belt, which scatters sunlight. In our solar system, anybody observing the skies on a moonless night far from city lights can see the sunlight that is scattered by dust in our asteroid belt. Called zodiacal light and sometimes the 'false dawn,' this light appears as a dim band stretching up from the horizon when the Sun is about to rise or set. The light is faint enough that the disk of our Milky Way galaxy remains the most prominent feature in the sky. (The Milky Way disk is shown perpendicular to the zodiacal light in both pictures.) In contrast, the zodiacal light in the HD 69830 system would be 1,000 times brighter than our own, outshining even the Milky Way.

  5. The atmospheric implications of radiation belt remediation

    Directory of Open Access Journals (Sweden)

    C. J. Rodger

    2006-08-01

    Full Text Available High altitude nuclear explosions (HANEs and geomagnetic storms can produce large scale injections of relativistic particles into the inner radiation belts. It is recognised that these large increases in >1 MeV trapped electron fluxes can shorten the operational lifetime of low Earth orbiting satellites, threatening a large, valuable population. Therefore, studies are being undertaken to bring about practical human control of the radiation belts, termed "Radiation Belt Remediation" (RBR. Here we consider the upper atmospheric consequences of an RBR system operating over either 1 or 10 days. The RBR-forced neutral chemistry changes, leading to NOx enhancements and Ox depletions, are significant during the timescale of the precipitation but are generally not long-lasting. The magnitudes, time-scales, and altitudes of these changes are no more significant than those observed during large solar proton events. In contrast, RBR-operation will lead to unusually intense HF blackouts for about the first half of the operation time, producing large scale disruptions to radio communication and navigation systems. While the neutral atmosphere changes are not particularly important, HF disruptions could be an important area for policy makers to consider, particularly for the remediation of natural injections.

  6. Seat belt use during pregnancy in Iran: attitudes and practices

    Institute of Scientific and Technical Information of China (English)

    Mojgan Karbakhsh; Zahra Ershadi; Ali Khaji; Fatemeh Rahimi-Sharbaf

    2010-01-01

    Objective: Seat belt use during pregnancy reduces injury to the mother and her fetus. During recent years, the use of seat belts has been mandated by law in Iran. The purpose of this study was to determine the attitudes and practices of pregnant women regarding seat belt use.Methods: In this cross-sectional study, we asked 335 pregnant women at a hospital-based prenatal care clinic on the use of safety belt before and during pregnancy. SPSS version 13.0 was used for data analysis.Results: The mean age of study subjects was 27.3 years±5.3 years with the median of 27 years. Compared with the seat belt use before pregnancy, no change was detected in 48.7% of the women; seat belt use had increased in 17.5 %of them and decreased in 33.8 %. Eighty-one percent of women knew the correct placing of both lap belt and shoulder belt. Only 4% of women had received education on proper restraint use during pregnancy.Conclusions: The prevalence of seat belt use during pregnancy is lower than reports which are mostly from developed nations. The fact that about one-third of women have decreased their seat belt usage during pregnancy highlights the importance of education of mothers on this topic.

  7. Taxi driver seat belt wearing in Nanjing, China.

    Science.gov (United States)

    Routley, Virginia; Ozanne-Smith, Joan; Qin, Yu; Wu, Ming

    2009-01-01

    To determine and validate patterns of seat belt use and attitudes of taxi drivers on wearing a seat belt following national and provincial seat belt legislation in 2004-2005. Roadside daylight seat belt observation and interview survey methods were used, as well as observations from inside taxis during routine trips and a taxi driver focus group. The setting was Nanjing, Jiangsu Province, PR China in April of 2006 and 2007. Prevalence of seat belt use and attitudes to wearing a seat belt were determined, as were vehicle and driver characteristics, and comparisons with other motor-vehicle driver's seat belt use and attitudes. Taxi drivers interviewed were predominantly male and aged 30-39 years. They spent more hours per week in their vehicles and had more driving experience than other drivers. Over half (56.2%) of taxi drivers interviewed reported that they always wore seat belts, while observation of taxi drivers showed lower wearing rates (i.e., roadside observation was 43.8%, and observation from inside taxis was 36.2%). Belt tampering was a practice of 12-15% of taxi drivers. "Fine avoidance, safety, high speed and long trips" were given as important reasons for wearing and "feeling trapped and uncomfortable" for not wearing. Seat belt reminder signs in taxis were common (82.6% of taxis), but did not appear to impact on driver seat belt use. The four research methods found taxi drivers to have consistently low "correct wearing" rates. As in several other countries, taxi drivers are particularly resistant to seat belt use. Innovative strategies, including occupational health and safety approaches, may be required to achieve increased levels of seat belt use.

  8. A great thermal divergence in the mantle beginning 2.5 Ga: Geochemical constraints from greenstone basalts and komatiites

    Directory of Open Access Journals (Sweden)

    Kent C. Condie

    2016-07-01

    Full Text Available Greenstone basalts and komatiites provide a means to track both mantle composition and magma generation temperature with time. Four types of mantle are characterized from incompatible element distributions in basalts and komatiites: depleted, hydrated, enriched and mantle from which komatiites are derived. Our most important observation is the recognition for the first time of what we refer to as a Great Thermal Divergence within the mantle beginning near the end of the Archean, which we ascribe to thermal and convective evolution. Prior to 2.5 Ga, depleted and enriched mantle have indistinguishable thermal histories, whereas at 2.5–2.0 Ga a divergence in mantle magma generation temperature begins between these two types of mantle. Major and incompatible element distributions and calculated magma generation temperatures suggest that Archean enriched mantle did not come from mantle plumes, but was part of an undifferentiated or well-mixed mantle similar in composition to calculated primitive mantle. During this time, however, high-temperature mantle plumes from dominantly depleted sources gave rise to komatiites and associated basalts. Recycling of oceanic crust into the deep mantle after the Archean may have contributed to enrichment of Ti, Al, Ca and Na in basalts derived from enriched mantle sources. After 2.5 Ga, increases in Mg# in basalts from depleted mantle and decreases in Fe and Mn reflect some combination of growing depletion and cooling of depleted mantle with time. A delay in cooling of depleted mantle until after the Archean probably reflects a combination of greater radiogenic heat sources in the Archean mantle and the propagation of plate tectonics after 3 Ga.

  9. Aortic ruptures in seat belt wearers.

    Science.gov (United States)

    Arajärvi, E; Santavirta, S; Tolonen, J

    1989-09-01

    Several investigations have indicated that rupture of the thoracic aorta is one of the leading causes of immediate death in victims of road traffic accidents. In Finland in 1983, 92% of front-seat passengers were seat belt wearers on highways and 82% in build-up areas. The mechanisms of rupture of the aorta have been intensively investigated, but the relationship between seat belt wearing and injury mechanisms leading to aortic rupture is still largely unknown. This study comprises 4169 fatally injured victims investigated by the Boards of Traffic Accident Investigation of Insurance Companies during the period 1972 to 1985. Chest injuries were recorded as the main cause of death in 1121 (26.9%) victims, 207 (5.0%) of those victims having worn a seat belt. Aortic ruptures were found at autopsy in 98 victims and the exact information of the location of the aortic tears was available in 68. For a control group, we analyzed 72 randomly chosen unbelted victims who had a fatal aortic rupture in similar accidents. The location of the aortic rupture in unbelted victims was more often in the ascending aorta, especially in drivers, whereas in seat belt wearers the distal descending aorta was statistically more often ruptured, especially in right-front passengers (p less than 0.05). The steering wheel predominated statistically as the part of the car estimated to have caused the injury in unbelted victims (37/72), and some interior part of the car was the most common cause of fatal thoracic impacts in seat belt wearers (48/68) (p less than 0.001). The mechanism of rupture of the aorta in the classic site just distal to the subclavian artery seems to be rapid deceleration, although complex body movements are also responsible in side impact collisions. The main mechanism leading to rupture of the ascending aorta seems to be severe blow to the bony thorax. This also often causes associated thoracic injuries, such as heart rupture and sternal fracture. Injuries in the ascending

  10. Modal analysis of coupled vibration of belt drive systems

    Institute of Scientific and Technical Information of China (English)

    LI Xiao-jun; CHEN Li-qun

    2008-01-01

    The modal method is applied to analyze coupled vibration of belt drive systems. A belt drive system is a hybrid system consisting of continuous belts modeled as strings as well as discrete pulleys and a tensioner arm. The characteristic equation of the system is derived from the governing equation. Numerical results demenstrate the effects of the transport speed and the initial tension on natural frequencies.

  11. Early Yellowstone hotspot magmatism and gold metallogeny

    Science.gov (United States)

    Hames, Willis; Unger, Derick; Saunders, James; Kamenov, George

    2009-11-01

    High-grade epithermal gold deposits in the Northern Great Basin have long been associated with regional Miocene basaltic to rhyolitic volcanism. Previous models for the low-sulfidation epithermal gold ores in this region have generally portrayed the bimodal magmas as a source of heat to drive large-scale convection of meteoritic water that leached gold from crustal sources and deposited it in hydrothermal vein systems, or required that the gold evolve from fractionated silicic magmas. New data of the present study indicate a more direct genetic link to the plume-related basaltic magmas of the region. Laser 40Ar/ 39Ar incremental heating plateau ages for single crystals of adularia from several of these low-sulfidation epithermal gold deposits range from 16.6 Ma to 15.5 Ma. Adularia from the Jumbo deposit yields three concordant plateau ages with a combined statistical result of 16.54 ± 0.04 Ma (95% confidence level, MSWD = 0.23). Plateau ages for adularia from other deposits in the region, and from gold-bearing veins in the Owyhee Mountains of southwestern Idaho, yield similar ages up to ~16.5 Ma, however some veins are as young as ca. 15.5 Ma and the grain-to-grain ages for a given sample can vary by up to ca. 0.5 Ma. Observed variations in age among the adularia crystals of a given rock sample indicate varying amounts of extraneous argon, and also loss of radiogenic 40Ar, among the population of grains for a particular sample. The single-crystal results are interpreted to indicate a 16.5-15.5 Ma interval for formation of gold-bearing adularia veins in the region. The initiation and duration of this gold-forming event appears contemporaneous (within uncertainties) with the basaltic volcanism at the Steens Mountain section and an ensuing one-million-year episode of basaltic volcanism from multiple centers in the region ( Brueseke et al., 2007). Trace amounts of lead are alloyed with gold in the deposits studied. The isotopic compositions of this lead are not compatible with regional crustal units that host the gold ores, or the silicic igneous lithologies of the region, but have the same lead isotopic composition as basalts of the earliest Yellowstone plume (represented by the earliest lavas of the Columbia River basalt province, the Steens basalts, and Stonyford Volcanic Complex; Hanan et al., 2008). We propose that the gold studied and its traces of alloyed lead were derived together from the mantle, released from basaltic magma chambers of the province, and carried by low-density fluids into shallow geothermal systems during the earliest stages of Yellowstone hotspot magmatism.

  12. Period Determination of Six Main Belt Asteroids

    Science.gov (United States)

    Ferrero, Andrea

    2014-07-01

    Observations of six main-belt asteroids (MBA) produced lightcurve parameters of: 487 Venetia, P = 13.34 ± 0.01 h, A = 0.20 mag; 684 Hildburg, P = 15.89 ± 0.01 h, A = 0.22 mag; 772 Tanete, P = 8.629 ± 0.001 h, A = 0.18 mag.; 1181 Lilith, P = 15.04 ± 0.01 h, A = 0.11 mag.; 1246 Chaka, P = 25.44 ± 0.01 h, A = 0.25 mag.; and 2834 Christy Carol, P = 12.79 ± 0.01 h, A = 0.39 mag.

  13. Water activities in the Kerala Khondalite Belt

    Science.gov (United States)

    Chacko, Thomas; Kumar, G. R. Ravindra; Peterson, J. W.

    1988-01-01

    The author and colleagues presented their determinations of water activities in various granulite-facies rocks of the Kerala Khondalite Belt. Using mineral equilibria, thermodynamic data, and assumed geopressure-geotemperature conditions of 5.5 kbar and 750 C, they calculated uniformly low a(H2O) values of about 0.27 over a large geographic region. They suggested that these conditions were produced by the presence of abundant CO2-rich fluids, derived either from deeper levels or from metamorphic reactions involving graphite.

  14. Linear Motor for Drive of Belt Conveyor

    Directory of Open Access Journals (Sweden)

    Milan Krasl

    2006-01-01

    Full Text Available This paper introduces a novel approach on the design of a linear motor for drive of belt conveyor (LMBC. The motor is a simple combination of asynchronous motor in plane. The electromagnetic forces is one of the most important parameters of electrical machines. This parameter is necessary for the checking of the design. This paper describes several variants: linear motor with slots in platens, slots in one half of platens and optimization of slots. The electromagnetic force can be found with the help of a Finite Elements Method – based program. For solution was used QuickField program.

  15. Solar Neutrons and the Earth's Radiation Belts.

    Science.gov (United States)

    Lingenfelter, R E; Flamm, E J

    1964-04-17

    The intensity and spectrum of solar neutrons in the vicinity of the earth are calculated on the assumption that the low-energy protons recently detected in balloon and satellite flights are products of solar neutron decay. The solar-neutron flux thus obtained exceeds the global average cosmic-ray neutron leakage above 10 Mev, indicating that it may be an important source of both the inner and outer radiation belts. Neutron measurements in the atmosphere are reviewed and several features of the data are found to be consistent with the estimated solar neutron spectrum.

  16. Parametric resonances of convection belt system

    Institute of Scientific and Technical Information of China (English)

    Zhi-an YANG; Gao-feng LI

    2009-01-01

    Based on the Coriolis acceleration and the Lagrangian strain formula,a generalized equation for the transverse vibration system of convection belts is derived using Newton's second law.The method of multiple scales is directly applied to the governing equations,and an approximate solution of the primary parameter resonance of the system is obtained.The detuning parameter,cross-section area,elastic and viscoelastic parameters,and axial moving speed have a significant influences on the amplitudes of steady-state response and their existence boundaries.Some new dynamical phenomena are revealed.

  17. Orion revisited. III. The Orion Belt population

    Science.gov (United States)

    Kubiak, K.; Alves, J.; Bouy, H.; Sarro, L. M.; Ascenso, J.; Burkert, A.; Forbrich, J.; Großschedl, J.; Hacar, A.; Hasenberger, B.; Lombardi, M.; Meingast, S.; Köhler, R.; Teixeira, P. S.

    2017-02-01

    Aims: This paper continues our study of the foreground population to the Orion molecular clouds. The goal is to characterize the foreground population north of NGC 1981 and to investigate the star formation history in the large Orion star-forming region. We focus on a region covering about 25 square degrees, centered on the ɛ Orionis supergiant (HD 37128, B0 Ia) and covering the Orion Belt asterism. Methods: We used a combination of optical (SDSS) and near-infrared (2MASS) data, informed by X-ray (XMM-Newton) and mid-infrared (WISE) data, to construct a suite of color-color and color-magnitude diagrams for all available sources. We then applied a new statistical multiband technique to isolate a previously unknown stellar population in this region. Results: We identify a rich and well-defined stellar population in the surveyed region that has about 2000 objects that are mostly M stars. We infer the age for this new population to be at least 5 Myr and likely 10 Myr and estimate a total of about 2500 members, assuming a normal IMF. This new population, which we call the Orion Belt population, is essentially extinction-free, disk-free, and its spatial distribution is roughly centered near ɛ Ori, although substructure is clearly present. Conclusions: The Orion Belt population is likely the low-mass counterpart to the Ori OB Ib subgroup. Although our results do not rule out Blaauw's sequential star formation scenario for Orion, we argue that the recently proposed blue streams scenario provides a better framework on which one can explain the Orion star formation region as a whole. We speculate that the Orion Belt population could represent the evolved counterpart of an Orion nebula-like cluster. The catalog (Full Table A.1) is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/598/A124

  18. CHAOTIC BELT PHENOMENA IN NONLINEAR ELASTIC BEAM

    Institute of Scientific and Technical Information of China (English)

    张年梅; 杨桂通

    2003-01-01

    The chaotic motions of axial compressed nonlinear elastic beam subjected totransverse load were studied. The damping force in the system is nonlinear. Consideringmaterial and geometric nonlinearity, nonlinear governing equation of the system wasderived. By use of nonlinear Galerkin method, differential dynamic system was set up.Melnikov method was used to analyze the characters of the system. The results showed thatchaos may occur in the system when the load parameters P0 and f satisfy some conditions.The zone of chaotic motion was belted. The route from subharmonic bifurcation to chaoswas analyzed. The critical conditions that chaos occurs were determined.

  19. The Radiation Belt Storm Probes Mission: Advancing Our Understanding of the Earth's Radiation Belts

    Science.gov (United States)

    Sibeck, David; Kanekal, Shrikanth; Kessel, Ramona; Fox, Nicola; Mauk, Barry

    2012-01-01

    We describe NASA's Radiation Belt Storm Probe (RBSP) mission, whose primary science objective is to understand, ideally to the point of predictability, the dynamics of relativistic electrons and penetrating ions in the Earth's radiation belts resulting from variable solar activity. The overarching scientific questions addressed include: 1. the physical processes that produce radiation belt enhancement events, 2. the dominant mechanisms for relativistic electron loss, and 3. how the ring current and other geomagnetic processes affect radiation belt behavior. The RBSP mission comprises two spacecraft which will be launched during Fall 2012 into low inclination lapping equatorial orbits. The orbit periods are about 9 hours, with perigee altitudes and apogee radial distances of 600 km and 5.8 RE respectively. During the two-year primary mission, the spacecraft orbits precess once around the Earth and lap each other twice in each local time quadrant. The spacecraft are each equipped with identical comprehensive instrumentation packages to measure, electrons, ions and wave electric and magnetic fields. We provide an overview of the RBSP mission, onboard instrumentation and science prospects and invite scientific collaboration.

  20. Effects of driver characteristics on seat belt fit.

    Science.gov (United States)

    Reed, Matthew P; Ebert, Sheila M; Hallman, Jason J

    2013-11-01

    A laboratory study of posture and belt fit was conducted with 46 men and 51 women, 61% of whom were age 60 years or older and 32% age 70 years or older. In addition, 28% of the 97 participants were obese, defined as body mass index ≥ 30 kg/m^2. A mockup of a passenger vehicle driver's station was created and five belt anchorage configurations were produced by moving the buckle, outboard-upper (D-ring), and outboard-lower anchorages. An investigator recorded the three-dimensional locations of landmarks on the belt and the participant's body using a coordinate measurement machine. The location of the belt with respect to the underlying skeletal structures was analyzed, along with the length of belt webbing. Using linear regression models, an increase in age from 20 to 80 years resulted in the lap belt positioned 18 mm further forward relative to the pelvis, 26 mm greater lap belt webbing length, and 19 mm greater shoulder belt length. An increase in stature of 350 mm (approximately the range from 5th-percentile female to 95th-percentile male in the U.S. population) was associated with the lap belt 14 mm further forward relative to the pelvis, the shoulder belt 37 mm more outboard relative to the body centerline, and 38 mm less shoulder belt webbing length. Among the driver factors considered, body mass index had the greatest effects. An increase of BMI in 20 kg/m^2, which spans approximately the central 90% of U.S. adults, was associated with the lap belt being placed 102 mm further forward and 94 mm higher, relative to the pelvis, and increases in lap and shoulder belt webbing length of 276 and 258 mm, respectively. Gender did not have important effects on the analyzed belt fit measures after taking into account stature and body mass index. These results offer important considerations for future crash safety assessments and suggest that further research is needed to consider belt fit for older and obese occupants.

  1. Fading of Jupiter's South Equatorial Belt

    Science.gov (United States)

    Sola, Michael A.; Orton, Glenn; Baines, Kevin; Yanamandra-Fisher, Padma

    2011-01-01

    One of Jupiter's most dominant features, the South Equatorial Belt, has historically gone through a "fading" cycle. The usual dark, brownish clouds turn white, and after a period of time, the region returns to its normal color. Understanding this phenomenon, the latest occurring in 2010, will increase our knowledge of planetary atmospheres. Using the near infrared camera, NSFCAM2, at NASA's Infrared Telescope Facility in Hawaii, images were taken of Jupiter accompanied by data describing the circumstances of each observation. These images are then processed and reduced through an IDL program. By scanning the central meridian of the planet, graphs were produced plotting the average values across the central meridian, which are used to find variations in the region of interest. Calculations using Albert4, a FORTRAN program that calculates the upwelling reflected sunlight from a designated cloud model, can be used to determine the effects of a model atmosphere due to various absorption, scattering, and emission processes. Spectra that were produced show ammonia bands in the South Equatorial Belt. So far, we can deduce from this information that an upwelling of ammonia particles caused a cloud layer to cover up the region. Further investigations using Albert4 and other models will help us to constrain better the chemical make up of the cloud and its location in the atmosphere.

  2. Distribution of dust from Kuiper belt objects

    CERN Document Server

    Gorkavyi, N N; Taidakova, T; Mather, J C; Gorkavyi, Nick N.; Ozernoy, Leonid M.; Taidakova, Tanya; Mather, John C.

    2000-01-01

    (Abridged) Using an efficient computational approach, we have reconstructed the structure of the dust cloud in the Solar system between 0.5 and 100 AU produced by the Kuiper belt objects. Our simulations offer a 3-D physical model of the `kuiperoidal' dust cloud based on the distribution of 280 dust particle trajectories produced by 100 known Kuiper belt objects ; the resulting 3-D grid consists of $1.9\\times 10^6$ cells containing $1.2\\times 10^{11}$ particle positions. The following processes that influence the dust particle dynamics are taken into account: 1) gravitational scattering on the eight planets (neglecting Pluto); 2) planetary resonances; 3) radiation pressure; and 4) the Poynting-Robertson (P-R) and solar wind drags. We find the dust distribution highly non-uniform: there is a minimum in the kuiperoidal dust between Mars and Jupiter, after which both the column and number densities of kuiperoidal dust sharply increase with heliocentric distance between 5 and 10 AU, and then form a plateau betwee...

  3. Chaotic Diffusion of Resonant Kuiper Belt Objects

    CERN Document Server

    Tiscareno, Matthew S

    2008-01-01

    We carried out extensive numerical orbit integrations to probe the long-term chaotic dynamics of the two strongest mean motion resonances of Neptune in the Kuiper belt, the 3:2 (Plutinos) and 2:1 (Twotinos). Our primary results include a computation of the relative volumes of phase space characterized by large- and small-resonance libration amplitudes, and maps of resonance stability measured by mean chaotic diffusion rate. We find that Neptune's 2:1 resonance has weaker overall long-term stability than the 3:2 -- only 15% of Twotinos are projected to survive for 4 Gyr, compared to 28% of Plutinos. We find that Pluto has only a modest effect, causing a ~4% decrease in the Plutino population that survives to 4 Gyr. Given current observational estimates, we conclude that the primordial populations of Plutinos and Twotinos formerly made up more than half the population of the classical and resonant Kuiper Belt. We also conclude that Twotinos were originally nearly as numerous as Plutinos, consistent with models ...

  4. The Dynamical Evolution of the Asteroid Belt

    CERN Document Server

    Morbidelli, Alessandro; O'Brien, David P; Minton, David A; Bottke, William F

    2015-01-01

    The asteroid belt is the leftover of the original planetesimal population in the inner solar system. However, currently the asteroids have orbits with all possible values of eccentricities and inclinations compatible with long-term dynamical stability, whereas the initial planetesimal orbits should have been quasi-circular and almost co-planar. The total mass in the asteroid population is a small fraction of that existing primordially. Also, asteroids with different chemical/mineralogical properties are not ranked in an orderly manner with mean heliocentric distance as one could expect from the existence of a radial gradient of the temperature in the proto-planetary disk, but they are partially mixed. These properties show that the asteroid belt has been severely sculpted by one or a series of processes during its lifetime. This paper reviews the processes that have been proposed so far, discussing the properties that they explain and the problems that they are confronted with. Emphasis is paid to the interpl...

  5. Young Stellar Objects in the Gould Belt

    CERN Document Server

    Dunham, Michael M; Evans, Neal J; Broekhoven-Fiene, Hannah; Cieza, Lucas; Di Francesco, James; Gutermuth, Robert A; Harvey, Paul M; Hatchell, Jennifer; Heiderman, Amanda; Huard, Tracy; Johnstone, Doug; Kirk, Jason M; Matthews, Brenda C; Miller, Jennifer F; Peterson, Dawn E; Young, Kaisa E

    2015-01-01

    We present the full catalog of Young Stellar Objects (YSOs) identified in the 18 molecular clouds surveyed by the Spitzer Space Telescope "cores to disks" (c2d) and "Gould Belt" (GB) Legacy surveys. Using standard techniques developed by the c2d project, we identify 3239 candidate YSOs in the 18 clouds, 2966 of which survive visual inspection and form our final catalog of YSOs in the Gould Belt. We compile extinction corrected SEDs for all 2966 YSOs and calculate and tabulate the infrared spectral index, bolometric luminosity, and bolometric temperature for each object. We find that 326 (11%), 210 (7%), 1248 (42%), and 1182 (40%) are classified as Class 0+I, Flat-spectrum, Class II, and Class III, respectively, and show that the Class III sample suffers from an overall contamination rate by background AGB stars between 25% and 90%. Adopting standard assumptions, we derive durations of 0.40-0.78 Myr for Class 0+I YSOs and 0.26-0.50 Myr for Flat-spectrum YSOs, where the ranges encompass uncertainties in the ado...

  6. Seat belt utilisation and awareness in UAE.

    Science.gov (United States)

    Bendak, S; Al-Saleh, K

    2013-01-01

    Seat belts (SBs) are effective devices for reducing injury risk due to traffic accidents. Seat belt wearing was made compulsory in the United Arab Emirates (UAE) in January 1999 for drivers and front seat passengers (FSPs). No comprehensive study has ever assessed SB wearing rates across the country. Also, little is known on drivers' awareness of the importance of wearing seatbelts and how human factors affect wearing habits. This study aims to determine SB wearing rates for drivers and FSPs in UAE through an observational field study. It also aims to investigate perceptions and behaviour of drivers on this issue as well as human factors that affect wearing rate through a randomly distributed questionnaire. The results of the field study show that the overall SB wearing rate across the country was 61% for drivers and 43.4% for FSPs and that there were significant differences between the seven emirates that constitute the country. The questionnaire results show that age, education level, gender, marital status and nationality of drivers affect wearing habits and perceptions. Future implications in terms of improving traffic safety awareness are discussed.

  7. Modulation of forelimb and hindlimb muscle activity during quadrupedal tied-belt and split-belt locomotion in intact cats.

    Science.gov (United States)

    Frigon, A; Thibaudier, Y; Hurteau, M-F

    2015-04-02

    The modulation of the neural output to forelimb and hindlimb muscles when the left and right sides step at different speeds from one another in quadrupeds was assessed by obtaining electromyography (EMG) in seven intact adult cats during split-belt locomotion. To determine if changes in EMG during split-belt locomotion were modulated according to the speed of the belt the limb was stepping on, values were compared to those obtained during tied-belt locomotion (equal left-right speeds) at matched speeds. Cats were chronically implanted for EMG, which was obtained from six muscles: biceps brachii, triceps brachii, flexor carpi ulnaris, sartorius, vastus lateralis and medial gastrocnemius. During tied-belt locomotion, cats stepped from 0.4 to 1.0m/s in 0.1m/s increments whereas during split-belt locomotion, cats stepped with left-right speed differences of 0.1 to 0.4m/s in 0.1m/s increments. During tied-belt locomotion, EMG burst durations and mean EMG amplitudes of all muscles respectively decreased and increased with increasing speed. During split-belt locomotion, there was a clear differential modulation of the EMG patterns between flexors and extensors and between the slow and fast sides. Changes in the EMG pattern of some muscles could be explained by the speed of the belt the limb was stepping on, while in other muscles there were clear dissociations from tied-belt values at matched speeds. Therefore, results show that EMG patterns during split-belt locomotion are modulated to meet task requirements partly via signals related to the stepping speed of the homonymous limb and from the other limbs.

  8. Ambient Response Analysis of the Great Belt Bridge

    DEFF Research Database (Denmark)

    Brincker, Rune; Frandsen, J. B.; Andersen, P.

    2000-01-01

    In this paper an ambient response analysis of the Great Belt Bridge is presented. The Great Belt Bridge is one of the largest suspension bridges in the world, and the analysis was carried out in order to investigate the possibilities of estimating reliable damping values from the ambient response...

  9. Increasing of horizontal velocity of particles leaving a belt conveyor

    Directory of Open Access Journals (Sweden)

    Tavares Abraão

    2017-01-01

    Full Text Available We investigate the transport of granular materials by a conveyor belt via numerical simulations. We report an unusual increasing of particles horizontal velocity when they leave the belt and initiate free-fall. Using Discrete Elements Method, the mechanism underlying this phenomenon were investigated, and a study on how particle and system properties influences this effect were conducted.

  10. Teaching Taekwondo in Physical Education: Incorporating the Color Belt System

    Science.gov (United States)

    Oh, Hyun-Ju; Hannon, James C.; Banks, Aaron

    2006-01-01

    Taekwondo is an excellent lifetime physical activity that provides both physical and mental benefits to its participants. The color belt system may be creatively used in physical education to encourage improvement in all learning domains. This article provides information on incorporating the color belt system into physical education, and provides…

  11. Respiratory Belt Transducer Constructed Using a Singing Greeting Card Beeper

    Science.gov (United States)

    Bhaskar, Anand; Subramani, Selvam; Ojha, Rajdeep

    2013-01-01

    An article by Belusic and Zupancic described the construction of a finger pulse sensor using a singing greeting card beeper. These authors felt that this beeper made of piezoelectric material could be easily modified to function as a respiratory belt transducer to monitor respiratory movements. Commercially available respiratory belt transducers,…

  12. Teaching Taekwondo in Physical Education: Incorporating the Color Belt System

    Science.gov (United States)

    Oh, Hyun-Ju; Hannon, James C.; Banks, Aaron

    2006-01-01

    Taekwondo is an excellent lifetime physical activity that provides both physical and mental benefits to its participants. The color belt system may be creatively used in physical education to encourage improvement in all learning domains. This article provides information on incorporating the color belt system into physical education, and provides…

  13. Respiratory Belt Transducer Constructed Using a Singing Greeting Card Beeper

    Science.gov (United States)

    Bhaskar, Anand; Subramani, Selvam; Ojha, Rajdeep

    2013-01-01

    An article by Belusic and Zupancic described the construction of a finger pulse sensor using a singing greeting card beeper. These authors felt that this beeper made of piezoelectric material could be easily modified to function as a respiratory belt transducer to monitor respiratory movements. Commercially available respiratory belt transducers,…

  14. Safety belt usage in Finland and in other Nordic countries.

    NARCIS (Netherlands)

    Valtonen, J.

    1992-01-01

    Legislation has played a significant role in increasing safety belt usage in Finland and in the other Nordic countries. Publicity and enforcement have, however, been required to support the legislation. The development of safety belt regulations has been nearly similar in all these countries, both i

  15. Canadian seat belt wearing rates, promotion programs, and future directions.

    NARCIS (Netherlands)

    Grant, B.A.

    1992-01-01

    On the basis of a national driver seat belt survey conducted in Canada each year, the most important results are presented. A number of programmes for increasing seat belt use has been evaluated in Canada. Finally, a description is given of some of the current and planned activities within Canada wh

  16. HUMAN NEURONAL INTERLIMB COORDINATION DURING SPLIT-BELT LOCOMOTION

    NARCIS (Netherlands)

    DIETZ, [No Value; ZIJLSTRA, W; DUYSENS, J

    1994-01-01

    Human interlimb coordination and the adaptations in leg muscle activity were studied during walking on a treadmill with split belts. Four different belt speeds (0.5, 1.0, 1.5, 2.0 m/s) were offered in all possible combinations for the left and right leg. Subjects adapted automatically to a differenc

  17. Human neuronal interlimb coordination during split-belt locomotion

    NARCIS (Netherlands)

    Dietz, V.; Zijlstra, W.G.; Duysens, J.E.J.

    1994-01-01

    Human interlimb coordination and the adaptations in leg muscle activity were studied during walking on a treadmill with split belts. Four different belt speeds (0.5, 1.0, 1.5, 2.0 m/s) were offered in all possible combinations for the left and right leg. Subjects adapted automatically to a differenc

  18. Biomechanical considerations for abdominal loading by seat belt pretensioners.

    Science.gov (United States)

    Rouhana, Stephen W; El-Jawahri, Raed E; Laituri, Tony R

    2010-11-01

    While seat belts are the most effective safety technology in vehicles today, there are continual efforts in the industry to improve their ability to reduce the risk of injury. In this paper, seat belt pretensioners and current trends towards more powerful systems were reviewed and analyzed. These more powerful systems may be, among other things, systems that develop higher belt forces, systems that remove slack from belt webbing at higher retraction speeds, or both. The analysis started with validation of the Ford Human Body Finite Element Model for use in evaluation of abdominal belt loading by pretensioners. The model was then used to show that those studies, done with lap-only belts, can be used to establish injury metrics for tests done with lap-shoulder belts. Then, previously-performed PMHS studies were used to develop AIS 2+ and AIS 3+ injury risk curves for abdominal interaction with seat belts via logistic regression and reliability analysis with interval censoring. Finally, some considerations were developed for a possible laboratory test to evaluate higher-powered pretensioners.

  19. Policy Implications from an Evaluation of Seat Belt Use Regulation.

    Science.gov (United States)

    Desai, Anand; You, Min-Bong

    1992-01-01

    Effects of Ohio's mandatory seat belt law on seat belt use, number of car accidents, and number of fatal and severe injuries were evaluated for January 1982 through March 1988. The monthly average number of accident victims was 2,002. Implications for public policy formulation and implementation are discussed. (SLD)

  20. An Evaluation of the Seat Belt Education Campaign.

    Science.gov (United States)

    Rochon, James

    A seat belt education campaign conducted in Canada to dispel myths surrounding seat belts and promote a better understanding of their functions was evaluated. Two telephone surveys, each comprised of 4,000 respondents, were conducted. The first was done immediately before the campaign and the second immediately succeeding the campaign. Also, a…

  1. Compliance with Seat Belt Use in Makurdi, Nigeria: An ...

    African Journals Online (AJOL)

    2011-03-23

    Mar 23, 2011 ... has been estimated that using seat belts can reduce the risk ... 24‑h direct observational study of seat belt usage among vehicle occupants in Makurdi, Benue. State ... In Nigeria, the Federal Road Safety Corps (FRSC) was.

  2. Experimental Measurements of Belt Gears in Newly Developed Device

    Directory of Open Access Journals (Sweden)

    Jozef Mascenik

    2016-05-01

    Full Text Available The paper deals with the alternative of determination of state of the belt gear. To realize themeasurements a newly developed device was designed for measurement and diagnostics of the belt gears. The main task is to detect the V-belt slip expressed by the coefficient of elastic creep and of specific slip with a measuring device. The measurements regarding can be performed if input revolutions of the electric motor and torque of the belt gear are constant whereas the tensioning force of the belt gear changes. It is also possible to perform the measurement if the input revolutions of the electric motor and the tensioning forces are constant and the torque changes.

  3. Nonoperative management of pediatric aortic injury with seat belt syndrome.

    Science.gov (United States)

    Parrish, Dan W; Barnhorst, Amanda; Trebska-McGowan, Katarzyna; Amendola, Michael; Haynes, Jeffrey H

    2015-08-01

    "Seat belt syndrome" was first described by Garret and Braunstein in 1962. The syndrome involves skin and abdominal wall ecchymosis (seat belt sign) intra-abdominal solid organ and visceral injuries, as well as Chance fractures (compression and/or wedging deformity of the anterior portion of the vertebral body with disruption or fracture of the posterior elements, generally at L1-L3). We present a case of a 12-year-old male involved in a high-speed motor vehicle collision wearing only a lap belt resulting in seat belt syndrome, with disruption of the abdominal wall, mesenteric avulsion with multiple intestinal perforations, abdominal aortic dissection, and an L2 Chance fracture with cord transection. Intraoperative decision making is outlined with this scenario of complex injuries, and the literature of seat belt syndrome associated with blunt aortic injuries and its management is reviewed.

  4. Survey of current situation in radiation belt modeling

    Science.gov (United States)

    Fung, Shing F.

    2004-01-01

    The study of Earth's radiation belts is one of the oldest subjects in space physics. Despite the tremendous progress made in the last four decades, we still lack a complete understanding of the radiation belts in terms of their configurations, dynamics, and detailed physical accounts of their sources and sinks. The static nature of early empirical trapped radiation models, for examples, the NASA AP-8 and AE-8 models, renders those models inappropriate for predicting short-term radiation belt behaviors associated with geomagnetic storms and substorms. Due to incomplete data coverage, these models are also inaccurate at low altitudes (e.g., radiation data from modern space missions and advancement in physical modeling and data management techniques have now allowed the development of new empirical and physical radiation belt models. In this paper, we will review the status of modern radiation belt modeling. Published by Elsevier Ltd on behalf of COSPAR.

  5. Landscape distribution characteristics of northern foothill belts of Tianshan Mountains

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The foothill belts of Tianshan Mountains are about 280 km long and 60 km wide, and the study area extends from Kuitun city to Fukang city. They are transitional belts between mountains and plains, appearing in three rows of folds with different morphologies and their age becoming younger from south to north. Based on GIS and RS methods, and materials of the previous researchers, this paper deals with the genetics of the foothill belts and their landscape features resulting from folding by neotectonic movements, and also describes their length, width and slope by remote sensing image interpretation. The characteristics of the foothill belts are found to be very important for the surrounding environment by preventing groundwater from flowing into plains, changing groundwater, increasing flow of surface runoff, in addition to their roles in protecting the surrounding environment. The purpose of this paper is to provide an in-depth understanding of the foothill belts and influence on its surrounding environment.

  6. Detecting extrasolar asteroid belts through their microlensing signatures

    Science.gov (United States)

    Lake, Ethan; Zheng, Zheng; Dong, Subo

    2017-02-01

    We propose that extrasolar asteroid belts can be detected through their gravitational microlensing signatures. Asteroid belt + star lens systems create so-called 'pseudo-caustics', regions in the source plane where the magnification exhibits a finite but discontinuous jump. These features allow such systems to generate distinctive signatures in the microlensing light curves for a wide range of belt configurations, with source trajectories as far as tenths of the Einstein ring radius from the centre of the lens. Sample light curves for a range of asteroid belt parameters are presented. In the near future, space-based microlensing surveys like WFIRST, which will have the power of detecting per cent-level changes in microlensing light curves even with subminute exposure times, may be able to discover extrasolar asteroid belts with masses of the order of an earth mass.

  7. Heads for shifting new generation of belt conveyors

    Energy Technology Data Exchange (ETDEWEB)

    Dembinski, M.

    1980-03-01

    New design of belt conveyors characterized by rigid section joints and conveyor to pontoon joints significantly influences loading of machines shifting belt conveyors to new locations. A new belt conveyor shifting machine head design, called SGP12 (selflocking head for vertical loads up to 120 kN) is described. Design is shown in 4 diagrams. It is stressed that in the SGP-12 the force clamping rollers on rails is automatically controlled depending on the height to which the rails are lifted. Clamping force is proportional to the height. This means of controlling the clamping force excludes damage to the head and reduces wear of the rollers. The SGP12 is, therefore, superior to the GP-12 shifting head of similar capacity. It is suggested that the SGP-12 is characterized by simple design, easier operation, higher reliability and greater safety. The SGP-12 can be used to shift belt conveyors with belts 2250 mm to 3000 mm wide.

  8. Radiation-belt dynamics during solar minimum. Technical report

    Energy Technology Data Exchange (ETDEWEB)

    Gussenhoven, M.S.; Mullen, E.G.; Holeman, E.

    1989-12-01

    Two types of temporal variation in the radiation belts are studied using low altitude data taken onboard the DMSP F7 satellite: those associated with the solar cycle and those associated with large magnetic storm effects. Over a three-year period from 1984 to 1987 and encompassing solar minimum, the protons in the heart of the inner belt increased at a rate of approximately 6% per year. Over the same period, outer zone electron enhancements declined both in number and peak intensity. During the large magnetic storm of February 1986, following the period of peak ring current intensity, a second proton belt with energies up to 50 MeV was found at magnetic latitudes between 45 deg. and 55 deg. The belt lasted for more than 100 days. The slot region between the inner and outer electron belts collapsed by the merging of the two populations and did not reform for 40 days.

  9. A Study on the Vibration of the Charging Belt in an Electrostatic Accelerator

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The vibration of the charging belt in an electrostatic accelerator has intense influences on the accelerator operation. A calculating model was set up in this paper to study the belt vibration. The results show that the belt tension, belt velocity and belt current all contribute to the belt vibration. There is an optimal relationship among the three factors by which the belt would run most smoothly. There exists a minimum value of optimal tension for various belt velocities. The vibrating frequency of the is generally around several Hz.

  10. Equilibria and Free Vibration of a Two-Pulley Belt-Driven System with Belt Bending Stiffness

    Directory of Open Access Journals (Sweden)

    Jieyu Ding

    2014-01-01

    Full Text Available Nonlinear equilibrium curvatures and free vibration characteristics of a two-pulley belt-driven system with belt bending stiffness and a one-way clutch are investigated. With nonlinear dynamical tension, the transverse vibrations of the translating belt spans and the rotation motions of the pulleys and the accessory shaft are coupled. Therefore, nonlinear piecewise discrete-continuous governing equations are established. Considering the bending stiffness of the translating belt spans, the belt spans are modeled as axially moving beams. The pattern of equilibria is a nontrivial solution. Furthermore, the nontrivial equilibriums of the dynamical system are numerically determined by using two different approaches. The governing equations of the vibration near the equilibrium solutions are derived by introducing a coordinate transform. The natural frequencies of the dynamical systems are studied by using the Galerkin method with various truncations and the differential and integral quadrature methods. Moreover, the convergence of the Galerkin truncation is investigated. Numerical results reveal that the study needs 16 terms after truncation in order to determine the free vibration characteristics of the pulley-belt system with the belt bending stiffness. Furthermore, the first five natural frequencies are very sensitive to the bending stiffness of the translating belt.

  11. The Stratigraphy and Lithofacies of the Paleoproterozoic Volcaniclastic Sequences in the Cape Three Points Area- Akodda section of the Southern in Ashanti Belt in the Birimian of southwest Ghana

    Science.gov (United States)

    Yoshimaru, S.; Kiyokawa, S.; Ito, T.; Ikehara, M.; Nyame, F. K.; Tetteh, G. M.

    2015-12-01

    The Paleoproterozoic Era is thought to have experienced one of the most significant changes in earth's environment during earth history. Early continents started to diverge and collide accompanied by first major oxidation of the atmosphere-oceanic system known as the Great Oxidation Environment (GOE). Due to their well-preserved oceanic sedimentary sequences, Paleoproterozoic belts are usually good targets for studies on the history of earth's past environment. In addition, these belts provide great help to understand the nature of the Paleoproterozoic deeper oceanic environments. Birimian greenstone belt in southwestern Ghana is likely to have made up of subduction of oceanic basin to form a volcanic island arc. Birimian rocks are separated by nonconformity from the Tarkwaian Group which is a younger paleoplacer deposit (Perrouty et al., 2012). The Birimian is made up of island-arc volcanic rocks; foreland basin made up of shale, sandstone, quartzite and turbidities derived from 2.17 Ga granite intrusions during Birimian volcanism. In this study, we focused on the coastal area around Cape Three Points at the southernmost part of the Ashanti (Axim-Konongo) belt in Ghana. In the eastern part of the area, excellently preserved Paleoprotorozoic deeper oceanic sedimentary sequences extensively outcrop for over 4km stretch. This volcano-sedimentary sequence has been affected by greenschist facies metamorphism. Structurally, this region preserves S1 cleavage and asymmetrical synform with west vergence and S0 younging to the east. Provisional stratigraphy is very continuous up to more than 2000m thick and, in addition, suggests at least four different fining upward sequences in the area to the east and west of Atwepo, west of Kwetakora and Akodda. These sub-sequences are mainly composed of volcaniclasitc, sandstone, black shale and rare volcanics such as pillow basalt or massive volcanic lava. In other words, this continuous sequence suggests distal submarine

  12. Main-belt comets: sublimation-driven activity in the asteroid belt

    CERN Document Server

    Hsieh, Henry H

    2015-01-01

    Our knowledge of main-belt comets (MBCs), which exhibit comet-like activity likely due to the sublimation of volatile ices, yet orbit in the main asteroid belt, has increased greatly since the discovery of the first known MBC, 133P/Elst-Pizarro, in 1996, and their recognition as a new class of solar system objects after the discovery of two more MBCs in 2005. I review work that has been done over the last 10 years to improve our understanding of these enigmatic objects, including the development of systematic discovery methods and diagnostics for distinguishing MBCs from disrupted asteroids (which exhibit comet-like activity due to physical disruptions such as impacts or rotational destabilization). I also discuss efforts to understand the dynamical and thermal properties of these objects.

  13. The JCMT Gould Belt Survey: Understanding the influence of molecular outflows on Gould Belt clouds

    CERN Document Server

    Drabek-Maunder, E; Buckle, J V; Di Francesco, J; Richer, J

    2015-01-01

    Using JCMT Gould Belt Survey data from CO J=3-2 isotopologues, we present a meta-analysis of the outflows and energetics of star-forming regions in several Gould Belt clouds. The majority of the regions are strongly gravitationally bound. There is evidence that molecular outflows transport large quantities of momentum and energy. Outflow energies are at least 20 per cent of the total turbulent kinetic energies in all of the regions studied and greater than the turbulent energy in half of the regions. However, we find no evidence that outflows increase levels of turbulence, and there is no correlation between the outflow and turbulent energies. Even though outflows in some regions contribute significantly to maintaining turbulence levels against dissipation, this relies on outflows efficiently coupling to bulk motions. Other mechanisms (e.g. supernovae) must be the main drivers of turbulence in most if not all of these regions.

  14. Ambient tremors in a collisional orogenic belt

    Science.gov (United States)

    Chuang, Lindsay Yuling; Chen, Kate Huihsuan; Wech, Aaron G.; Byrne, Timothy; Peng, Wei

    2014-01-01

    Deep-seated tectonic tremors have been regarded as an observation tied to interconnected fluids at depth, which have been well documented in worldwide subduction zones and transform faults but not in a collisional mountain belt. In this study we explore the general features of collisional tremors in Taiwan and discuss the possible generation mechanism. In the 4 year data, we find 231 ambient tremor episodes with durations ranging from 5 to 30 min. In addition to a coseismic slip-induced stress change from nearby major earthquake, increased tremor rate is also highly correlated with the active, normal faulting earthquake swarms at the shallower depth. Both the tremor and earthquake swarm activities are confined in a small, area where the high attenuation, high thermal anomaly, the boundary between high and low resistivity, and localized veins on the surfaces distributed, suggesting the involvement of fluids from metamorphic dehydration within the orogen.

  15. NASA's Radiation Belt Storm Probe Mission

    Science.gov (United States)

    Sibeck, David G.

    2011-01-01

    NASA's Radiation Belt Storm Probe (RBSP) mission, comprising two identically-instrumented spacecraft, is scheduled for launch in May 2012. In addition to identifying and quantifying the processes responsible for energizing, transporting, and removing energetic particles from the Earth's Van Allen radiation, the mission will determine the characteristics of the ring current and its effect upon the magnetosphere as a whole. The distances separating the two RBSP spacecraft will vary as they move along their 1000 km altitude x 5.8 RE geocentric orbits in order to enable the spacecraft to separate spatial from temporal effects, measure gradients that help identify particle sources, and determine the spatial extent of a wide array of phenomena. This talk explores the scientific objectives of the mission and the manner by which the mission has been tailored to achieve them.

  16. East Central Uplift Belt of Junggar Basin

    Institute of Scientific and Technical Information of China (English)

    1996-01-01

    @@ Mosuowandong ( Z3 ) and Dongdaohaizi (Z4) are two bidding blocks located in the east part of central uplift Belt, the hinterland of Junggar Basin. Xinjiang Uygur Autonomous Region. It totally covers an area of 8 100km2. Topographically, the two blocks are quite gentle with elevation of 380-400 m on average. The north part is desert and the south area is good for farming. There are three ephemeral streams flowing across the desert from south to north. The ground water is buried at the depth ranging from 6 to 8 m. It belongs to continental climate with the annually averaged precipitation of 80 mm. The traffic is rather convenient in the south part of both blocks. There are several sand-paved roads and two asphalt roads connected with the highway from Karamay to Urumqi City.

  17. Subsurface Meridional Circulation in the Active Belts

    CERN Document Server

    Hernandez, I Gonzalez; Hill, F; Howe, R; Komm, R

    2008-01-01

    Temporal variations of the subsurface meridional flow with the solar cycle have been reported by several authors. The measurements are typically averaged over periods of time during which surface magnetic activity existed in the regions were the velocities are calculated. The present work examines the possible contamination of these measurements due to the extra velocity fields associated with active regions plus the uncertainties in the data obtained where strong magnetic fields are present. We perform a systematic analysis of more than five years of GONG data and compare meridional flows obtained by ring-diagram analysis before and after removing the areas of strong magnetic field. The overall trend of increased amplitude of the meridional flow towards solar minimum remains after removal of large areas associated with surface activity. We also find residual circulation toward the active belts that persist even after the removal of the surface magnetic activity, suggesting the existence of a global pattern o...

  18. Oscillations control of a transmission belt by Excitation Clipping using Clutch Clamping Control (E4C)

    Science.gov (United States)

    Temporelli, Robin; Micheau, Philippe

    2017-04-01

    A transmission belt deals with non-linear phenomena such as parametric excitations that can bring the belt in an instability region resulting in large transverse oscillations. These oscillations can cause belt life deflection, noise and unexpected vibration on its environment. The present study proposes a new strategy to control oscillations of a transmission belt subject to periodic tension fluctuations. Indeed, for a transmission belt, periodic torque fluctuations cause periodic belt tension fluctuations which can be a source of excitation for the belt and resulting in belt oscillations under certain conditions. The presence of a clutch between the belt end-point and the source of torque fluctuations offers a means to clip torque fluctuations and thus to clip belt excitation. In keeping with this notion, belt oscillations can be controlled by an Excitation Clipping using Clutch Clamping Control (E4C) strategy. Through an example of a transmission belt subject to periodic tension fluctuations, the E4C strategy is presented and a new analytical model of belt behavior with its E4C strategy is constructed. Free belt oscillations (E4C is not activated) and controlled belt oscillations (E4C is activated) are observed through an experimental setup and predicted owing to the new analytical model. Finally, the E4C strategy leads to frequency unlocking that successfully removes belt oscillations. This new analytical model furthermore provides an accurate prediction of belt behavior with its E4C strategy.

  19. Geometry, kinematics and evolution of the Tongbai orogenic belt

    Institute of Scientific and Technical Information of China (English)

    HUANG Shaoying; XU Bei; WANG Changqiu; ZHAN Sheng; DENG Rongjing

    2006-01-01

    The Tongbai orogenic belt (TOB) is composed of six tectonic units. From south to north these units are: Tongbai gneiss rise (TGR); Hongyihe-Luozhuang eclogite belt (HLE); Maopo-Hujiazhai igneous rock belt (MHI); Zhoujiawan flysch belt (ZFB); Yangzhuang greenschist belt (YGB); and Dongjiazhuang marble belt (DMB).The geometry and kinematic images of the TOB include: the antiformal structures caused by a later uplift process, the top-to-north ductile shear structure that related to a process that the ultrahigh pressure rocks are brought to surface, the top-to-south ductile shear thrust and the sinistrial shear structures related to a south-north direction compression, and the east-west direction fold structures in the upper crust. In the view of the multistage subduction-collision orogenic belt, according to the characters of petrology and its distribution, geometry, kinematics and structural chronology in these tectonic units, tectonic evolution of the TOB can be divided into four stages: oceanic crust subduction during 400-300 Ma, continental collision during 270-250 Ma, continental deep subduction and uplift during 250-205 Ma and doming deformation during 200-185 Ma.

  20. North Florida is part of the stroke belt.

    OpenAIRE

    Siegel, P. Z.; Wolfe, L E; Wilcox, D.; Deeb, L C

    1992-01-01

    Florida is the only State in the southeastern United States that is not part of the "stroke belt." The National Heart, Lung, and Blood Institute (NHLBI), National Institutes of Health, defines the stroke belt as those States with an age-adjusted stroke mortality rate for the years 1979 to 1981 that is more than 10 percent above the national annual rate of 40.3 per 100,000 population. By reproducing at the county level the methods that were used at the State level to describe the stroke belt, ...

  1. Radiation Belt Storm Probes: Resolving Fundamental Physics with Practical Consequences

    Science.gov (United States)

    Ukhorskiy, Aleksandr Y.; Mauk, Barry H.; Fox, Nicola J.; Sibeck, David G.; Grebowsky, Joseph M.

    2011-01-01

    The fundamental processes that energize, transport, and cause the loss of charged particles operate throughout the universe at locations as diverse as magnetized planets, the solar wind, our Sun, and other stars. The same processes operate within our immediate environment, the Earth's radiation belts. The Radiation Belt Storm Probes (RBSP) mission will provide coordinated two-spacecraft observations to obtain understanding of these fundamental processes controlling the dynamic variability of the near-Earth radiation environment. In this paper we discuss some of the profound mysteries of the radiation belt physics that will be addressed by RBSP and briefly describe the mission and its goals.

  2. Human neuronal interlimb coordination during split-belt locomotion

    OpenAIRE

    Dietz, V; Zijlstra, W G; Duysens, J.E.J.

    1994-01-01

    Human interlimb coordination and the adaptations in leg muscle activity were studied during walking on a treadmill with split belts. Four different belt speeds (0.5, 1.0, 1.5, 2.0 m/s) were offered in all possible combinations for the left and right leg. Subjects adapted automatically to a difference in belt speed within 10–20 stride cycles.This adaptation was achieved by a reorganization of the stride cycle with a relative shortening of the duration of the support and lengthening of the swin...

  3. Resistance and other parameters of belt conveyor shifting

    Energy Technology Data Exchange (ETDEWEB)

    Dembinski, M.

    1988-07-01

    Discusses a method developed by Poltegor for calculating energy consumption of belt conveyor shifting in brown coal surface mines in Poland. A program for simulating effects of all significant factors that represent the environment, physical and mechanical properties of soil, effects of weather and atmospheric precipitations, design of belt conveyors, effects of soil or coal buildup and conveyor wear is used. Indices that describe effects of major groups of factors are used for calculating resistance to belt conveyor shifting considering local conditions. Investigations carried out in the Belchatow brown coal mine show the method to be accurate and reliable.

  4. Power Transmission Through Timing Belt In Two Wheeler Motors

    Directory of Open Access Journals (Sweden)

    Gurumurthy Veerapathiran

    2015-03-01

    Full Text Available This paper studies the effect of noise and friction on performance of the chain drive system for motor bikes. Experiment shows that chain transmission in chain drive system leads to poor overall performance, due to its noise and chain gets loose due to aging and sprockets wear due to chain friction etc., the proposed system consists of drive and driven pulley with timing belt transmission. Compared to conventional method, proposed method give improved tension in pulleys and belt by the additional arrangement called belt tensioner. This gives good overall performance of the system, and reduces noise, vibration and gives high transmission speed.

  5. Effect of one-way clutch on the nonlinear vibration of belt-drive systems with a continuous belt model

    Science.gov (United States)

    Ding, Hu; Zu, Jean W.

    2013-11-01

    This study focuses on the nonlinear steady-state response of a belt-drive system with a one-way clutch. A dynamic model is established to describe the rotations of the driving pulley, the driven pulley, and the accessory shaft. Moreover, the model considers the transverse vibration of the translating belt spans for the first time in belt-drive systems coupled with a one-way clutch. The excitation of the belt-drive system is derived from periodic fluctuation of the driving pulley. In automotive systems, this kind of fluctuation is induced by the engine firing harmonic pulsations. The derived coupled discrete-continuous nonlinear equations consist of integro-partial-differential equations and piece-wise ordinary differential equations. Using the Galerkin truncation, a set of nonlinear ordinary differential equations is obtained from the integro-partial-differential equations. Applying the Runge-Kutta time discretization, the time histories of the dynamic response are numerically solved for the driven pulley and the accessory shaft and the translating belt spans. The resonance areas of the coupled belt-drive system are determined using the frequency sweep. The effects of the one-way clutch on the belt-drive system are studied by comparing the frequency-response curves of the translating belt with and without one-way clutch device. Furthermore, the results of 2-term and 4-term Galerkin truncation are compared to determine the numerical convergence. Moreover, parametric studies are conducted to understand the effects of the system parameters on the nonlinear steady-state response. It is concluded that one-way clutch not only decreases the resonance amplitude of the driven pulley and shaft's rotational vibration, but also reduces the resonance region of the belt's transverse vibration.

  6. Trio of Neptunes and their Belt

    Science.gov (United States)

    2006-05-01

    Using the ultra-precise HARPS spectrograph on ESO's 3.6-m telescope at La Silla (Chile), a team of European astronomers have discovered that a nearby star is host to three Neptune-mass planets. The innermost planet is most probably rocky, while the outermost is the first known Neptune-mass planet to reside in the habitable zone. This unique system is likely further enriched by an asteroid belt. ESO PR Photo 18a/06 ESO PR Photo 18a/06 Planetary System Around HD 69830 (Artist's Impression) "For the first time, we have discovered a planetary system composed of several Neptune-mass planets", said Christophe Lovis, from the Geneva Observatory and lead-author of the paper presenting the results [1]. During more than two years, the astronomers carefully studied HD 69830, a rather inconspicuous nearby star slightly less massive than the Sun. Located 41 light-years away towards the constellation of Puppis (the Stern), it is, with a visual magnitude of 5.95, just visible with the unaided eye. The astronomers' precise radial-velocity measurements [2] allowed them to discover the presence of three tiny companions orbiting their parent star in 8.67, 31.6 and 197 days. "Only ESO's HARPS instrument installed at the La Silla Observatory, Chile, made it possible to uncover these planets", said Michel Mayor, also from Geneva Observatory, and HARPS Principal Investigator. "Without any doubt, it is presently the world's most precise planet-hunting machine" [3]. ESO PR Photo 18d/06 ESO PR Photo 18d/06 Phase Folded Measurements of HD 69830 The detected velocity variations are between 2 and 3 metres per second, corresponding to about 9 km/h! That's the speed of a person walking briskly. Such tiny signals could not have been distinguished from 'simple noise' by most of today's available spectrographs. The newly found planets have minimum masses between 10 and 18 times the mass of the Earth. Extensive theoretical simulations favour an essentially rocky composition for the inner planet, and

  7. 30 CFR 57.14131 - Seat belts for surface haulage trucks.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Seat belts for surface haulage trucks. 57.14131... and Equipment Safety Devices and Maintenance Requirements § 57.14131 Seat belts for surface haulage trucks. (a) Seat belts shall be provided and worn in haulage trucks. (b) Seat belts shall be...

  8. Practical and medical aspects of the use of car seat belts.

    NARCIS (Netherlands)

    Edelman, A. & Kampen, L.T.B. van

    1974-01-01

    An analysis is made of the influence of use and non-use of seat belts on type and severity of injuries to drivers and of the influence of seat belt type on type and severity of injuries to drivers. Users of lap belts and users of 3-point belts enjoy a comparable and considerable reduction of injury

  9. MACRO MODEL OF SEAT BELT USE BY CAR DRIVERS AND PASSENGERS

    Directory of Open Access Journals (Sweden)

    Kazimierz JAMROZ

    2013-12-01

    Full Text Available The article presents some problems of seat belt use by car drivers and passengers. It looks in particular at seat belt use and effectiveness in selected countries. Next, factors of seat belt use are presented and methodology of model development. A macro model of seat belt use is presented based on data from around fifty countries from different continents.

  10. Feasibility of electro-osmotic belt filter dewatering technology at pilot scale

    CSIR Research Space (South Africa)

    Snyman, HG

    2000-01-01

    Full Text Available -effective dewatering technologies, electro-osmotic belt filtering was developed by Smollen and Kafaar in 1995. The mechanical equipment resembles a belt filter press but the belts are stainless steel, woven belts, which act as the electrodes. In this study...

  11. FORMATION AND EVOLUTION OF THE CENOZOIC THRUST FOLD BELT IN JINPING, SICHUAN

    Institute of Scientific and Technical Information of China (English)

    LIAO Zhongli; DENG Yongfu; LIAO Guangyu

    2003-01-01

    The Jinping orogenic belt in Sichuan, China consists mainly of the Jinpingshan intracontinental thrust-nappe belt, foreland thrust-nappe belt and foreland uplift belt. Based on analyses about the characteristics of the structural units in this area, the authors propose in this paper that Chapuzi-Bazhe revival fault belt is the regional boundary fault, and points out that after the formation of the Pre-Sinian basement, the western edge of the Yangtze paraplatform was turned into the passive continental margin in Sinian to Triassic, then into the Mesozoic collision orogenic belt, and finally into the Cenozoic orogenic belt through intracontinental orogeny.

  12. "Abomination"--life as a Bible belt gay.

    Science.gov (United States)

    Barton, Bernadette

    2010-01-01

    Drawing on observation, autoethnography, and audio-taped interviews, this article explores the religious backgrounds and experiences of Bible Belt gays. In the Bible Belt, Christianity is not confined to Sunday worship. Christian crosses, messages, paraphernalia, music, news, and attitudes permeate everyday settings. Consequently, Christian fundamentalist dogma about homosexuality-that homosexuals are bad, diseased, perverse, sinful, other, and inferior-is cumulatively bolstered within a variety of other social institutions and environments in the Bible Belt. Of the 46 lesbians and gay men interviewed for this study (age 18-74 years), most describe living through spirit-crushing experiences of isolation, abuse, and self-loathing. This article argues that the geographic region of the Bible Belt intersects with religious-based homophobia. Informants explained that negative social attitudes about homosexuality caused a range of harmful consequences in their lives including the fear of going to hell, depression, low self-esteem, and feelings of worthlessness.

  13. Back belts in occupational setting: what are the evidences?

    Directory of Open Access Journals (Sweden)

    João Marcos Bernardes

    2012-01-01

    Full Text Available Although, widely used the mechanisms of action and the effectiveness of back belts in the prevention of occupational low back disorders remains uncertain, generating controversy about its use. Therefore, the purpose of this study was to do a critical literature review about back belts use in the prevention of occupational low back pain in the occupational setting. In order to do that, a bibliographic research in the following data basis: Medline, SciELO and LILACS was conducted. There is evidence that back belts use reduces spine range of motion, however the studies about intra-abdominal pressure and muscle activity presented contradictory results, as the epidemiologic studies, not allowing the recommendation of its use in the prevention of occupational low back pain. Based on this literature review it is suggested therefore, the implementation of new studies, to confirm or not the effectiveness of back belts as personal protective equipment, in the prevention of occupational low back disorders.

  14. Jupiter's radiation belt ions - A comparison of theory and observation

    Science.gov (United States)

    Summers, Danny; Thorne, Richard M.; Mei, YI

    1989-01-01

    Radial profiles are constructed for the Jovian radiation belt flux-tube content Y-asterisk from the reported phase-space density of energetic particles obtained from Voyager 1 data over the range L = 6 to L = 9. These experimental profiles are compared with theoretical solutions for Y-asterisk from an interchange-diffusion model of the coupled radiation belt and Iogenic ion populations. Subject to certain limitations of the Voyager 1 data, the model solutions are found to be consistent with the data for a variety of input parameters. Model solutions are also found corresponding to radiation belt ions that are expected to be mainly responsible for the auroral energy input. Comparison of the present theoretical profiles with the data implies that the energetic radiation belt ions should have a peak loss rate within a factor of three of that for strong diffusion scattering.

  15. CRED REA Fish Team Belt Transect Survey at Laysan 2004

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Belt transects along 3 consecutively-placed, 25m transect lines were surveyed as part of Rapid Ecological Assessments conducted at 3 sites at Laysan in the Northwest...

  16. Periumbilical allergic contact dermatitis: blue jeans or belt buckles?

    Science.gov (United States)

    Byer, Tara T; Morrell, Dean S

    2004-01-01

    Nickel is the most ubiquitous contact allergen among children and adolescents. Metal blue jeans buttons and belts have been noted to cause nickel dermatitis around the umbilicus. For these children, traditional teaching is strict avoidance of all pants with metal snaps/buttons, particularly blue jeans. In this study we tested 90 pairs of blue jeans and 47 belts for nickel using the dimethylglyoxime spot test. Only 10% of blue jeans tested positive, while 53% of belts tested positive. Furthermore, 10 pairs of nickel-negative blue jeans remained negative after 10 washings. Overall we found no resistance to testing in clothing stores. From these results, we recommend that patients with allergic contact dermatitis secondary to nickel need not strictly avoid blue jeans and metal belt buckles. Rather, families should be encouraged to use the dimethylglyoxime spot test to test these items for nickel prior to purchase.

  17. 5m Main Belt Asteroid Population Estimation Using Vesta Imagery

    Science.gov (United States)

    Rynders, Michael; Trilling, David E.

    2016-10-01

    The Main Belt is the largest source of Near-Earth asteroids, but objects 2 pixels in diameter that were counted in a 33km 2 region to give a crater density. By knowing the crater density and making some reasonable assumptions about the orbital distribution of asteroids and the age of Vesta's surface, an estimate of the population of small asteroids in the inner main belt was made. It was found that the inner region of the main asteroid belt contains approximately 20 billion asteroids larger than 5 m. These results agree well with the measured inner Main Belt Size distribution derived by the Wide-field Infrared Survey Explorer, WISE (Masiero et al. 2011).

  18. Cenozoic intracontinental deformation of the Kopeh Dagh Belt, Northeastern Iran

    Science.gov (United States)

    Chu, Yang; Wan, Bo; Chen, Ling; Talebian, Morteza

    2016-04-01

    Compressional intracontinental orogens represent large tectonic zones far from plate boundaries. Since intracontinental mountain belts cannot be framed in the conventional plate tectonics theory, several hypotheses have been proposed to account for the formations of these mountain belts. The far-field effect of collision/subduction at plate margins is now well accepted for the origin and evolution of the intracontinental crust thickening, as exemplified by the Miocene tectonics of central Asia. In northern Iran, the Binalud-Alborz mountain belt witnessed the Triassic tectonothermal events (Cimmerian orogeny), which are interpreted as the result of the Paleotethys Ocean closure between the Eurasia and Central Iran blocks. The Kopeh Dagh Belt, located to the north of the Binalud-Alborz Belt, has experienced two significant tectonic phases: (1) Jurassic to Eocene rifting with more than 7 km of sediments; and (2) Late Eocene-Early Oligocene to Quaternary continuous compression. Due to the high seismicity, deformation associated with earthquakes has received more and more attention; however, the deformation pattern and architecture of this range remain poorly understood. Detailed field observations on the Cenozoic deformation indicate that the Kopeh Dagh Belt can be divided into a western zone and an eastern zone, separated by a series of dextral strike-slip faults, i.e. the Bakharden-Quchan Fault System. The eastern zone characterized by km-scale box-fold structures, associated with southwest-dipping reverse faults and top-to-the NE kinematics. In contrast, the western zone shows top-to-the SW kinematics, and the deformation intensifies from NE to SW. In the northern part of this zone, large-scale asymmetrical anticlines exhibit SW-directed vergence with subordinate thrusts and folds, whereas symmetrical anticlines are observed in the southern part. In regard to its tectonic feature, the Kopeh Dagh Belt is a typical Cenozoic intracontinental belt without ophiolites or

  19. Design of MGA trajectories for main belt asteroid

    Institute of Scientific and Technical Information of China (English)

    崔祜涛; 乔栋; 崔平远; 栾恩杰

    2003-01-01

    Asteroid exploration is one of the most sophisticated missions currently being investigated. Gravityassist trajectories have proven valuable in interplanetary missions such as the Pioneer, Voyager and Galileo. In this paper, we design interplanetary trajectory for main belt asteroid exploration mission with the Mars gravityassist (MGA) using "pork chop" plots and patched-conic theory and give some initial valuable trajectory parameters on main belt asteroid exploration mission with MGA.

  20. The Role of Plasma in Radiation Belt Loss.

    Science.gov (United States)

    Jahn, J. M.; Bonnell, J. W.; Kurth, W. S.; Millan, R. M.; Goldstein, J.; Jaynes, A. N.; Blake, J. B.; Denton, R. E.

    2015-12-01

    The radiation belts are zones of relativistic electrons encircling the Earth. Their radial structure is controlled by the competition between source and loss processes. Most commonly, a two-belt structure prevails, though a more complicated three-belt structure - an inner belt plus two outer electron belts - have repeatedly been observed. The plasma conditions that enable and enhance loss-facilitating wave activity in the inner magnetosphere are still under discussion. Relativistic electrons have been thought to more easily resonate with electromagnetic ion-cyclotron waves (EMIC) when the total plasma density is large (i.e., in the plasmasphere and plume). However, there is evidence that this interaction may be not as strong as thought, and that instead the field-aligned motion of lower energy ring current ions (up to a few 10's keV) may play a key role. Similarly, the exact influence of large heavy ion (O+) concentrations remains unsettled. We use 2.5+ years of Van Allen Probes observations to study the region of plasmasphere-outer belt overlap (and its vicinity). By now, the Van Allen Probes provide a complete and very dense coverage of the complete magnetosphere inside geosynchronous orbit We focus our interest on understanding the plasma conditions that can favor EMIC wave growth. We investigate the temperature anisotropy A (modified by plasma β) of the warm/hot plasma, and contrast it with the location specifics of the plasmasphere (i.e., very high total density) and the occurrence of high O+ concentrations in the overlap regions with the radiation belt(s). We present both average conditions for all parameters during a variety of geomagnetic conditions, and highlight specific loss and overlap events in an effort to establish favorable plasma conditions for relativistic electron loss during those times.

  1. Trapped radiation belts of saturn: first look.

    Science.gov (United States)

    Fillius, W; Ip, W H; McIlwain, C E

    1980-01-25

    Pioneer 11 has made the first exploration of the magnetosphere and trapped radiation belts of Saturn. Saturn's magnetosphere is intermediate in size between Earth's and Jupiter's, with trapped particle intensities comparable to Earth's. The outer region of Saturn's magnetosphere contains lower energy radiation and is variable with time; the inner region contains higher energy particles. The pitch angle distributions show a remarkable variety of field-aligned and locally mirroring configurations. The moons and especially the rings of Saturn are effective absorbers of trapped particles; underneath the rings, the trapped radiation is completely absorbed. We confirm the discovery of a new ring, called the F ring, a new division, the Pioneer division, and a moon, called 1979 S 2. The latter has probably been seen from Earth. There may be evidence for more bodies like 1979 S 2, but at this stage the interpretation of the data is ambiguous. Using particle diffusion rates, we estimate that the cross-sectional area of the F ring is > 7 x 10(13) square centimeters and that the opacity is > 10(-5). Cosmic-ray albedo neutron decay should be looked into as a source of energetic particles in the inner magnetosphere of Saturn.

  2. Radiation Belt Electron Dynamics: Modeling Atmospheric Losses

    Science.gov (United States)

    Selesnick, R. S.

    2003-01-01

    The first year of work on this project has been completed. This report provides a summary of the progress made and the plan for the coming year. Also included with this report is a preprint of an article that was accepted for publication in Journal of Geophysical Research and describes in detail most of the results from the first year of effort. The goal for the first year was to develop a radiation belt electron model for fitting to data from the SAMPEX and Polar satellites that would provide an empirical description of the electron losses into the upper atmosphere. This was largely accomplished according to the original plan (with one exception being that, for reasons described below, the inclusion of the loss cone electrons in the model was deferred). The main concerns at the start were to accurately represent the balance between pitch angle diffusion and eastward drift that determines the dominant features of the low altitude data, and then to accurately convert the model into simulated data based on the characteristics of the particular electron detectors. Considerable effort was devoted to achieving these ends. Once the model was providing accurate results it was applied to data sets selected from appropriate periods in 1997, 1998, and 1999. For each interval of -30 to 60 days, the model parameters were calculated daily, thus providing good short and long term temporal resolution, and for a range of radial locations from L = 2.7 to 3.9. .

  3. Trapped radiation belts of Saturn - First look

    Science.gov (United States)

    Fillius, W.; Ip, W. H.; Mcilwain, C. E.

    1980-01-01

    Data on the magnetosphere of Saturn obtained with the trapped radiation detector package on board the Pioneer 11 spacecraft is reported. Radiation belt profiles determined by the trapped radiation detectors on Pioneer 10 and 11 indicate that Saturn's magnetosphere is intermediate in size between those of the earth and Jupiter, with particle intensities similar to those of the earth. The outer region of the Saturn magnetosphere is found to contain particles of lower energy than the outer region, being strongly influenced by the time-varying solar wind. The moons and rings of Saturn are observed to be effective absorbers of trapped particles, confirming the discoveries of the F ring, the Pioneer ring division and the moon 1979 S 2. Particle diffusion rates are used to estimate a cross-sectional area of greater than 7 x 10 to the 13th sq cm and an opacity greater than 0.00001 for the F ring. It is suggested that cosmic-ray albedo neutron decay be studied as a possible source of energetic particles in the inner magnetosphere of Saturn.

  4. Politicians and Epidemics in the Bible Belt

    Directory of Open Access Journals (Sweden)

    Geurt Henk Spruyt

    2016-07-01

    Full Text Available The Netherlands has a high vaccination coverage, but due to a concentration of people objecting to vaccination on religious grounds in the Bible belt, several polio and measles epidemics have occurred there in the past. This article analyses how and in what way Dutch politicians responded to parents refusing to have their children vaccinated. First, during these epidemics Members of Parliament mainly addressed written questions of a highly technical or procedural nature to the responsible State Secretary or Minister of Public Health. Secondly, the government always requested advice from an advisory body with regard to matters of health after an epidemic. These reports were opposed to mandatory vaccination mainly by using practical arguments. However, by advocating the idea of strengthening the position of minors in public healthcare these reports contributed to legislation codifying the rights of minors concerning public health. The most important rationale behind this response is the complexity of the issue of mandatory vaccination, because different human rights are involved. On the one hand, mandatory vaccination infringes the constitutional rights to the freedom of thought, conscience and religion and encroaches on parental autonomy. On the other hand, children have a right to physical integrity. To find a way out of this unsolvable dilemma, the government and its advisory bodies mainly used practical arguments against mandatory vaccination.

  5. Orion revisited III. The Orion Belt population

    CERN Document Server

    Kubiak, K; Bouy, H; Sarro, L M; Ascenso, J; Burkert, A; Forbrich, J; Großschedl, J; Hacar, A; Hasenberger, B; Lombardi, M; Meingast, S; Köhler, R; Teixeira, P S

    2016-01-01

    This paper continues our study of the foreground population to the Orion molecular clouds. The goal is to characterize the foreground population north of NGC 1981 and to investigate the star formation history in the large Orion star-forming region. We focus on a region covering about 25 square degrees, centered on the $\\epsilon$ Orionis supergiant (HD 37128, B0\\,Ia) and covering the Orion Belt asterism. We used a combination of optical (SDSS) and near-infrared (2MASS) data, informed by X-ray (\\textit{XMM-Newton}) and mid-infrared (WISE) data, to construct a suite of color-color and color-magnitude diagrams for all available sources. We then applied a new statistical multiband technique to isolate a previously unknown stellar population in this region. We identify a rich and well-defined stellar population in the surveyed region that has about 2\\,000 objects that are mostly M stars. We infer the age for this new population to be at least 5\\, Myr and likely $\\sim10$\\,Myr and estimate a total of about 2\\,500 mem...

  6. Dark nebulae, dark lanes, and dust belts

    CERN Document Server

    Cooke, Antony

    2012-01-01

    As probably the only book of its type, this work is aimed at the observer who wants to spend time with something less conventional than the usual fare. Because we usually see objects in space by means of illumination of one kind or another, it has become routine to see them only in these terms. However, part of almost everything that we see is the defining dimension of dark shading, or even the complete obscuration of entire regions in space. Thus this book is focused on everything dark in space: those dark voids in the stellar fabric that mystified astronomers of old; the dark lanes reported in many star clusters; the magical dust belts or dusty regions that have given so many galaxies their identities; the great swirling 'folds' that we associate with bright nebulae; the small dark feature detectable even in some planetary nebulae; and more. Many observers pay scant attention to dark objects and details. Perhaps they are insufficiently aware of them or of the viewing potential they hold, but also it may be...

  7. Politicians and Epidemics in the Bible Belt

    Directory of Open Access Journals (Sweden)

    Geurt Henk Spruyt

    2016-07-01

    Full Text Available The Netherlands has a high vaccination coverage, but due to a concentration of people objecting to vaccination on religious grounds in the Bible belt, several polio and measles epidemics have occurred there in the past. This article analyses how and in what way Dutch politicians responded to parents refusing to have their children vaccinated. First, during these epidemics Members of Parliament mainly addressed written questions of a highly technical or procedural nature to the responsible State Secretary or Minister of Public Health. Secondly, the government always requested advice from an advisory body with regard to matters of health after an epidemic. These reports were opposed to mandatory vaccination mainly by using practical arguments. However, by advocating the idea of strengthening the position of minors in public healthcare these reports contributed to legislation codifying the rights of minors concerning public health. The most important rationale behind this response is the complexity of the issue of mandatory vaccination, because different human rights are involved. On the one hand, mandatory vaccination infringes the constitutional rights to the freedom of thought, conscience and religion and encroaches on parental autonomy. On the other hand, children have a right to physical integrity. To find a way out of this unsolvable dilemma, the government and its advisory bodies mainly used practical arguments against mandatory vaccination.

  8. The Gould Belt, the de Vaucouleurs-Dolidze Belt, and the Orion Arm

    OpenAIRE

    Bobylev, V. V.; Bajkova, A. T.

    2014-01-01

    Based on masers with measured trigonometric parallaxes, we have redetermined the spatial orientation parameters of the Local (Orion) arm. Using 23 sources (the Gould Belt objects were excluded), we have found that their spatial distribution can be approximated by a very narrow ellipsoid elongated in the direction L_1=77.1+/-2.9^o whose symmetry plane is inclined to the Galactic plane at an angle of 5.6+/-0.2^o. The longitude of the ascending node of the symmetry plane is l_\\Omega=70+/-3^o. A ...

  9. Forming the Cold Classical Kuiper Belt in a light Disk

    CERN Document Server

    Shannon, Andrew; Lithwick, Yoram

    2015-01-01

    Large Kuiper Belt Objects are conventionally thought to have formed out of a massive planetesimal belt that is a few thousand times its current mass. Such a picture, however, is incompatible with multiple lines of evidence. Here, we present a new model for the conglomeration of Cold Classical Kuiper belt objects, out of a solid belt only a few times its current mass, or a few percent of the solid density in a Minimum Mass Solar Nebula. This is made possible by depositing most of the primordial mass in grains of size centimetre or smaller. These grains collide frequently and maintain a dynamically cold belt out of which large bodies grow efficiently: an order-unity fraction of the solid mass can be converted into large bodies, in contrast to the ~0.1% efficiency in conventional models. Such a light belt may represent the true outer edge of the Solar system, and it may have effectively halted the outward migration of Neptune. In addition to the high efficiency, our model can also produce a mass spectrum that pe...

  10. Seat Belts Pay Off. The Use of Economic Incentives and Public Education to Increase Seat Belt Use in a Community. Final Report.

    Science.gov (United States)

    Campbell, B. J.; And Others

    A six-month campaign to increase seat belt use in Chapel Hill and Carrboro, North Carolina centered around the idea of giving out economic incentives for seat belt wearing. The approach was to stop vehicles at random and give all belted vehicle occupants a small prize and a chance for a large cash prize. Precampaign activities involve collecting…

  11. Evaluation of legislation on seat belt use on rear seats : social persuasion as a new measure to promote seat belt use.

    NARCIS (Netherlands)

    Oei, H.-l.

    1996-01-01

    In the Netherlands, the use of seat belts for front seat passengers was made compulsory in 1975, and on April 1st 1992 the use of rear seat belts, if fitted, became a legal requirement. Since 1968, an annual survey of the presence and use of seat belts on front seats - extended in 1989 to include re

  12. Evaluation of legislation on seat belt use on rear seats : social persuasion as a new measure to promote seat belt use.

    NARCIS (Netherlands)

    Oei, H.-l.

    1996-01-01

    In the Netherlands, the use of seat belts for front seat passengers was made compulsory in 1975, and on April 1st 1992 the use of rear seat belts, if fitted, became a legal requirement. Since 1968, an annual survey of the presence and use of seat belts on front seats - extended in 1989 to include

  13. Meningococcal carriage in the African meningitis belt

    Science.gov (United States)

    2013-01-01

    A meningococcal serogroup A polysaccharide/tetanus toxoid conjugate vaccine (PsA-TT) (MenAfriVac#x2122;) is being deployed in countries of the African meningitis belt. Experience with other polysaccharide/protein conjugate vaccines has shown that an important part of their success has been their ability to prevent the acquisition of pharyngeal carriage and hence to stop transmission and induce herd immunity. If PsA-TT is to achieve the goal of preventing epidemics, it must be able to prevent the acquisition of pharyngeal carriage as well as invasive meningococcal disease and whether PsA-TT can prevent pharyngeal carriage needs to be determined. To address this issue, a consortium (the African Meningococcal Carriage (MenAfriCar) consortium) was established in 2009 to investigate the pattern of meningococcal carriage in countries of the African meningitis belt prior to and after the introduction of PsA-TT. This article describes how the consortium was established, its objectives and the standardised field and laboratory methods that were used to achieve these objectives. The experience of the MenAfriCar consortium will help in planning future studies on the epidemiology of meningococcal carriage in countries of the African meningitis belt and elsewhere. Un vaccin conjugué contenant un polysaccharide du sérogroupe A méningococcique et une anatoxine du tétanos (PsA-TT) (MenAfriVac™) est en cours de déploiement dans les pays de la ceinture africaine de la méningite. L’ expérience avec d’ autres vaccins conjugués polysaccharide/protéine a montré qu’ une partie importante de leur succès a été leur capacité à empêcher l’ acquisition du portage pharyngé et donc à arrêter la transmission et à induire une immunité de group. Si PsA-TT doit d’ atteindre l’ objectif de prévenir les épidémies, il devrait être en mesure d’ empêcher l’ acquisition du portage pharyngé ainsi que la méningococcie invasive et le fait que PsA-TT puisse emp

  14. The relationship between the plasmapause and outer belt electrons

    Science.gov (United States)

    Goldstein, J.; Baker, D. N.; Blake, J. B.; De Pascuale, S.; Funsten, H. O.; Jaynes, A. N.; Jahn, J.-M.; Kletzing, C. A.; Kurth, W. S.; Li, W.; Reeves, G. D.; Spence, H. E.

    2016-09-01

    We quantify the spatial relationship between the plasmapause and outer belt electrons for a 5 day period, 15-20 January 2013, by comparing locations of relativistic electron flux peaks to the plasmapause. A peak-finding algorithm is applied to 1.8-7.7 MeV relativistic electron flux data. A plasmapause gradient finder is applied to wave-derived electron number densities >10 cm-3. We identify two outer belts. Outer belt 1 is a stable zone of >3 MeV electrons located 1-2 RE inside the plasmapause. Outer belt 2 is a dynamic zone of plasma density. Belt 1 decayed on hiss timescales prior to a disturbance on 17 January and suffered only a modest dropout, perhaps owing to shielding by the plasmasphere. Afterward, the partially depleted belt 1 continued to decay at the initial rate. Belt 2 was emptied out by strong disturbance-time losses but restored within 24 h. For global context we use a plasmapause test particle simulation and derive a new plasmaspheric index Fp, the fraction of a circular drift orbit inside the plasmapause. We find that the locally measured plasmapause is (for this event) a good proxy for the globally integrated opportunity for losses in cold plasma. Our analysis of the 15-20 January 2013 time interval confirms that high-energy electron storage rings can persist for weeks or even months if prolonged quiet conditions prevail. This case study must be followed up by more general study (not limited to a 5 day period).

  15. Biomechanics of 4-point seat belt systems in farside impacts.

    Science.gov (United States)

    Rouhana, Stephen W; Kankanala, Sundeep V; Prasad, Priya; Rupp, Jonathan D; Jeffreys, Thomas A; Schneider, Lawrence W

    2006-11-01

    The biomechanical behavior of a harness style 4-point seat belt system in farside impacts was investigated through dummy and post mortem human subject tests. Specifically, this study was conducted to evaluate the effect of the inboard shoulder belt portion of a 4-point seat belt on the risk of vertebral and soft-tissue neck injuries during simulated farside impacts. Two series of sled tests simulating farside impacts were completed with crash dummies of different sizes, masses and designs to determine the forces and moments on the neck associated with loading of the shoulder belt. The tests were also performed to help determine the appropriate dummy to use in further testing. The BioSID and SID-IIs reasonably simulated the expected kinematics response and appeared to be reasonable dummies to use for further testing. Analysis also showed that dummy injury measures were lower than injury assessment reference values used in development of side impact airbags. Six post-mortem human subjects, three small females and three medium sized males, were tested under conditions similar to those used for the dummy tests. The carotid arteries were pressurized in an attempt to simulate the corresponding neck vascular response of living humans. Post-test autopsies conducted on all test subjects indicated an absence of test-induced arterial or vertebral injuries. Further, comparative analysis of kinematics confirmed the adequacy of the BioSID and SID-IIs in simulating cadaveric response in farside impacts with harness style 4-point belts. A number of issues remain to be solved before the implementation of 4-point seat belts in vehicles, including, among others, the risk of injury to a pregnant woman and her fetus in frontal crashes. The risk of fetal injury in pregnant occupants may be related to the location of the 4-point seat belt's buckle and latch junction at the centerline of the mother's abdomen.

  16. Digital Spectra and Analysis of Altitudinal Belts in Tianshan Mountains,China

    Institute of Scientific and Technical Information of China (English)

    ZHANG Baiping; MO Shenguo; WU Hongzhi; XIAO Fei

    2004-01-01

    Based on the framework of the geo-info spectra of montane altitudinal belts, this paper firstly reviews six classification systems for the spectra of mountain altitudinal belts in China and considers that detailed regional study of altitudinal belts is the key for reaching standardization and systemization of mountain altitudinal belts. Only can this furtheridentify and resolve problems with the study of altitudinal belts. The factors forming the spectra of altitudinal belts are analyzed in the Tianshan Mountains of China, and a digital altitudinal belt system is constructed for the northern flank, Southern flank, the heartland, and Ilivalley in the west. The characteristics of each belt are revealed with a summarization of the pattern of areal differentiation of altitudinal belts.

  17. 23 CFR 1240.12 - Determination of State seat belt use rate for calendar year 1998 and beyond.

    Science.gov (United States)

    2010-04-01

    ... 23 Highways 1 2010-04-01 2010-04-01 false Determination of State seat belt use rate for calendar... FOR USE OF SEAT BELTS-ALLOCATIONS BASED ON SEAT BELT USE RATES Determination of Allocations § 1240.12 Determination of State seat belt use rate for calendar year 1998 and beyond. (a) State seat belt use survey....

  18. Formation and Dynamical Evolution of the Asteroid Belt

    Science.gov (United States)

    Bottke, William F.

    2015-08-01

    Asteroids are critical to our desire to unravel the origin of the Solar System because they supply unique, relatively pristine snapshots of the environment in which the Earth formed and evolved. This is due to the fact that, although the asteroids and Earth have followed very different evolutionary pathways, they all formed from the same set of physical processes and share a common ancestry. The asteroid belt presents a particular challenge to understanding terrestrial planet formation because of its small mass. Models of the protoplanetary disk suggest the region between 2-3 AU should contain roughly 3 Earth masses, while less than 0.001 of an Earth mass is actually found there.A long-standing explanation for the asteroid belt's small mass is that it is due to the gravitational influence of Jupiter and Saturn. Some have suggested protoplanets grew there before they were dynamically removed from the asteroid belt by resonances with the gas giants. This left the asteroid belt dynamically excited (which is observed) and heavily depleted in mass. More recently, however, detailed models have shown that this process produces an asteroid belt that is inconsistent with observations.Two recent models propose new ways to match asteroid belt constraints. The first, the so-called ‘Grand Tack’ scenario, uses the results of hydrodynamic simulations to show that Jupiter (and Saturn) migrated both inward and outward across the asteroid belt while interacting with the protoplanetary gas disk. The Grand Tack not only reproduces the mass and mixture of spectral types in the asteroid belt, but it also truncates the planetesimal disk from which the terrestrial planets form, potentially explaining why Mars is less massive than Earth. In a second scenario, planetesimals that form directly from cm- to meter-sized objects, known as “pebbles”, are rapidly converted to 100 to 1000 km asteroid-like object that subsequently grow by accreting even more pebbles. Pebble accretion models

  19. A Physical Model of Electron Radiation Belts of Saturn

    Science.gov (United States)

    Lorenzato, L.; Sicard-Piet, A.; Bourdarie, S.

    2012-04-01

    Radiation belts causes irreversible damages on on-board instruments materials. That's why for two decades, ONERA proposes studies about radiation belts of magnetized planets. First, in the 90's, the development of a physical model, named Salammbô, carried out a model of the radiation belts of the Earth. Then, for few years, analysis of the magnetosphere of Jupiter and in-situ data (Pioneer, Voyager, Galileo) allow to build a physical model of the radiation belts of Jupiter. Enrolling on the Cassini age and thanks to all information collected, this study permits to adapt Salammbô jovian radiation belts model to the case of Saturn environment. Indeed, some physical processes present in the kronian magnetosphere are similar to those present in the magnetosphere of Jupiter (radial diffusion; interaction of energetic electrons with rings, moons, atmosphere; synchrotron emission). However, some physical processes have to be added to the kronian model (compared to the jovian model) because of the particularity of the magnetosphere of Saturn: interaction of energetic electrons with neutral particles from Enceladus, and wave-particle interaction. This last physical process has been studied in details with the analysis of CASSINI/RPWS (Radio and Plasma Waves Science) data. The major importance of the wave particles interaction is now well known in the case of the radiation belts of the Earth but it is important to investigate on its role in the case of Saturn. So, importance of each physical process has been studied and analysis of Cassini MIMI-LEMMS and CAPS data allows to build a model boundary condition (at L = 6). Finally, results of this study lead to a kronian electrons radiation belts model including radial diffusion, interactions of energetic electrons with rings, moons and neutrals particles and wave-particle interaction (interactions of electrons with atmosphere particles and synchrotron emission are too weak to be taken into account in this model). Then, to

  20. Evolution of the Bhandara-Balaghat granulite belt along the southern margin of the Sausar Mobile Belt of central India

    Indian Academy of Sciences (India)

    H M Ramachandra; Abhinaba Roy

    2001-12-01

    The Bhandara-Balaghat granulite (BBG) belt occurs as a 190 km long, detached narrow, linear, NE-SW to ENE-WSW trending belt that is in tectonic contact on its northern margin with the Sausar Group of rocks and is bordered by the Sakoli fold belt in the south. The Bhandara part of the BBG belt is quite restricted, comprising a medium to coarse grained two-pyroxene granulite body that is of gabbroic composition and preserves relic igneous fabric. The main part of the belt in Arjuni-Balaghat section includes metasedimentary (quartzite, BIF, Al- and Mg-Al metapelites) and metaigneous (metaultramafic, amphibolite and two-pyroxene granulite) protoliths interbanded with charnockite and charnockitic gneiss. These rocks, occurring as small bands and enclaves within migmatitic and granitic gneisses, show polyphase deformation and metamorphism. Geochemically, basic compositions show tholeiitic trend without Fe-enrichment, non-komatitic nature, continental affinity and show evolved nature. Mineral parageneses and reaction textures in different rock compositions indicate early prograde, dehydration melt forming reactions followed by orthopyroxene stability with or without melt. Coronitic and symplectitic garnets have formed over earlier minerals indicating onset of retrograde IBC path. Evidences for high temperature ductile shearing are preserved at places. Retrogressive hydration events clearly post-date the above paths. The present study has shown that the BBG belt may form a part of the Bastar Craton and does not represent exhumed oceanic crust of the Bundelkhand Craton. It is further shown that rocks of the BBG belt have undergone an earlier high-grade granulite metamorphism at 2672 ± 54 Ma (Sm-Nd age) and a post-peak granulite metamorphism at 1416 ± 59 Ma (Sm-Nd age, 1380 ± 28 Ma Rb-Sr age). These events were followed by deposition of the Sausar supracrustals and Neoproterozoic Sausar orogeny between 973 ± 63 Ma and 800 ± 16 Ma (Rb-Sr ages).

  1. Out-of-sequence thrusting in polycyclic thrust belts: An example from the Mesozoic Yanshan belt, North China Craton

    Science.gov (United States)

    Li, Chengming; Zhang, Changhou; Cope, Tim D.; Lin, Yi

    2016-09-01

    The EW trending Yanshan belt, an intraplate fold-thrust belt located in the northern North China Craton that has experienced several episodes of deformation widely separated in time, is characterized by out-of-sequence thrusts. According to detailed mapping in the central Yanshan belt, five geometric and stratigraphic criteria used to aid in determining whether a thrust has an out-of-sequence geometry or not can be recognized. They are (1) unconformable relationships, (2) inclination of fault surfaces, (3) irregular changes in apparent offset along strike, (4) short fault length relative to apparent offset, and (5) in-sequence geometry. With the help of these criteria, two generations of out-of-sequence thrusts that postdate the original in-sequence thrusting in the central Yanshan belt are recognized. The ancestral southward verging fold-and-thrust belt that formed prior to 180 Ma was deformed and cut by two younger generations of faults that are probably more deeply rooted and are constrained to between 172-165 Ma and 152-135 Ma. A series of thrusts with opposite vergence formed during the last period, resulting in abundant abnormal field relationships such as younger-on-older thrust relations, fold truncation, and cutting down-section. The nature and occurrence of faults in the Yanshan belt implies that superimposed deformation, a common feature in polycyclic orogenic belts, is a mechanism for the generation of out-of-sequence thrusting. This adds to mechanisms already described in the literature, such as maintaining constant critical taper at an orogenic scale, inhibition of the deformation front, and lateral changes in the nature of the décollement horizons.

  2. Reliability models of belt drive systems under slipping failure mode

    Directory of Open Access Journals (Sweden)

    Peng Gao

    2017-01-01

    Full Text Available Conventional reliability assessment and reliability-based optimal design of belt drive are based on the stress–strength interference model. However, the stress–strength interference model is essentially a static model, and the sensitivity analysis of belt drive reliability with respect to design parameters needs further investigations. In this article, time-dependent factors that contribute the dynamic characteristics of reliability are pointed out. Moreover, dynamic reliability models and failure rate models of belt drive systems under the failure mode of slipping are developed. Furthermore, dynamic sensitivity models of belt drive reliability based on the proposed dynamic reliability models are proposed. In addition, numerical examples are given to illustrate the proposed models and analyze the influences of design parameters on dynamic characteristics of reliability, failure rate, and sensitivity functions. The results show that the statistical properties of design parameters have different influences on reliability and failure rate of belt drive in cases of different values of design parameters and different operational durations.

  3. SEAT BELT USE AMONG CAR USERS IN MALAYSIA

    Directory of Open Access Journals (Sweden)

    S. KULANTHAYAN

    2004-01-01

    Full Text Available The car is the second (40% most common mode of transportation in Malaysia. In terms of fatal road accidents, car drivers constitute about 9.0% and passengers 13.6% of fatalities. The major cause of car occupants' fatality in such accidents is head injuries, which consist of more than half (56.4% of the fatalities. Thus restraining the head and body, the initial position is the most important injury control strategy for car users. The use of seat belts was deemed one of the most effective ways to reduce road accident fatalities in Malaysia and consequently the mandatory seat belt law was enforced in the early seventies. Therefore, a study on factors influencing the compliance behaviour of seat belt use among cars is needed as to date no such research has been undertaken in Malaysia. A questionnaire study was carried out in Selangor, Malaysia on the compliance behaviour of car occupants in relation to seat belt use. A total of 237 respondents were interviewed and the data analysed using logistic regression method. Six variables were found to be significant at 5 percent level (p<0.05: seating position, location of travel, education level, speeding, night-time driving and enforcement. Compliance with the seat belt law was higher among drivers, educated car users, in the presence of enforcement activities, travelling in city-center areas and car users with a positive attitude towards the risks of speeding and night driving.

  4. Fall Protection Characteristics of Safety Belts and Human Impact Tolerance.

    Science.gov (United States)

    Hino, Yasumichi; Ohdo, Katsutoshi; Takahashi, Hiroki

    2014-08-23

    Many fatal accidents due to falls from heights have occurred at construction sites not only in Japan but also in other countries. This study aims to determine the fall prevention performance of two types of safety belts: a body belt(1)), which has been used for more than 40 yr in the Japanese construction industry as a general type of safety equipment for fall accident prevention, and a full harness(2, 3)), which has been used in many other countries. To determine human tolerance for impact trauma, this study discusses features of safety belts with reference(4-9)) to relevant studies in the medical science, automobile crash safety, and aircrew safety. For this purpose, simple drop tests were carried out in a virtual workplace to measure impact load, head acceleration, and posture in the experiments, the Hybrid-III pedestrian model(10)) was used as a human dummy. Hybrid-III is typically employed in official automobile crash tests (New Car Assessment Program: NCAP) and is currently recognized as a model that faithfully reproduces dynamic responses. Experimental results shows that safety performance strongly depends on both the variety of safety belts used and the shock absorbers attached onto lanyards. These findings indicate that fall prevention equipment, such as safety belts, lanyards, and shock absorbers, must be improved to reduce impact injuries to the human head and body during falls.

  5. Flat belt continuously variable high speed drive. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Kumm, E.L.

    1992-02-01

    A study was undertaken at Kumm Industries funded by DOE in the NBS/DOE Energy-Related Inventions Program starting in August 1990 to design, construct and test a novel very high speed flat belt drive. The test arrangement as shown in Figure 1 consists of a multiple belt-pulley configuration that transmits power from a low speed (2000--4000 RPM) input to a small pulley ``turbine`` (27,000 to 55,000 RPM) and then to the low speed output variable radius pulley (2000--5000 RPM) via a special self-active tensioner. Transmitting 25 HP to and from the ``turbine`` corresponds to obtaining 50 HP in one direction only in a possible turbo compounded engine application. The high speed of the ``turbine`` belts, i.e. 100 meters/sec. at 55,000 RPM, while transferring substantial power is a new much higher operating regime for belts. The study showed that the available belts gave overall test rig efficiencies somewhat above 80% for the higher speeds (50,000 RPM) and higher powers (corresponding to above 90% in the turbocompound application) and a significantly better efficiencies at slightly lower speeds. The tests revealed a number of improved approaches in the design of such high speed drives. It appears that there is considerable possibility for further improvement and application of such equipment.

  6. Spectrophotometry of Kuiper Belt Objects and Centaurs

    Science.gov (United States)

    Lederer, S. M.; Vilas, F.

    2002-09-01

    We present an ongoing study of Kuiper Belt Objects (KBOs) and Centaurs. We acquired broadband (UBVRI) and medium band photometry with the 4m Mayall telescope at Kitt Peak and the 1.8m Perkins telescope at Lowell Observatory. We present broadband colors of these objects and discuss the results of our search for absorption bands in the visible spectral region. Vilas (Icarus, 111) demonstrated that the existence of the 0.7um absorption feature in asteroids with solar-like colors was strongly correlated with the presence of the 3.0um water of hydration feature. The broad 0.7um absorption band is attributed to a charge-transfer in Fe-bearing hydrated silicates (phyllosilicates), which are a product of aqueous alteration. For aqueous alteration to take place, one must have water ice present in an object, and an energy source to heat the water ice to a liquid water phase. Water ice has already been discovered in some Centaurs (Luu et al. ApJ, 531; Brown AJ, 119), and Durda and Stern (Icarus, 145) estimate that KBOs experience collisional processing regularly throughout their lifetimes. The estimated impact energies are high enough to induce aqueous alteration. We undertook this study to search for evidence of the 0.7um feature in KBOs and Centaurs. We employed medium band Windhorst filters, located at 0.527, 0.666, 0.705, 0.755 and 0.848 um in conjunction with the Mosaic CCD to search for this absorption band, which extends from 0.57-0.83um. Initial analysis suggests that an absorption feature exists near 0.7um in the greyer objects but not the redder objects, following the correlations observed in asteroids. These data are consistent with the absorption band detected near 0.7um by de Bergh et al. (ACM 2002, Berlin) in visible spectra of 2000 EB173 and 2000 GN171. However, further analysis is required to confirm whether the absorption we see is due to phyllosilicates or another source. We will present the results from this analysis. This research was supported through the

  7. Research on Dynamic Tension for Belt Conveyor with Constant Force Automatic Take-Up Assembly

    Institute of Scientific and Technical Information of China (English)

    MENG Guo-ying; CHEN Jing-li; LI Yu-jin

    2003-01-01

    The article Provides a dynamic model for belt conveyor. Based on the drive-force of conveyor, take-up tension of take-up assembly, gravity of conveyor belt and material, and friction between belt and idlers, it gives a viscoelastic dynamic equation for conveyor belt. It presents a calculation method of analytic solution to both viscoelastic dynamic equation and geometric dynamic equation when automatic take-up assembly is applied to belt conveyor. The article also makes a study of design method of limiting and eliminating the conveyor belt's elastic vibration.

  8. Belt(s) of debris resolved around the Sco-Cen star HIP 67497

    Science.gov (United States)

    Bonnefoy, M.; Milli, J.; Ménard, F.; Vigan, A.; Lagrange, A.-M.; Delorme, P.; Boccaletti, A.; Lazzoni, C.; Galicher, R.; Desidera, S.; Chauvin, G.; Augereau, J. C.; Mouillet, D.; Pinte, C.; van der Plas, G.; Gratton, R.; Beust, H.; Beuzit, J. L.

    2017-01-01

    Aims: In 2015, we initiated a survey of Scorpius-Centaurus A-F stars that are predicted to host warm-inner and cold-outer belts of debris similar to the case of the system HR 8799. The survey aims to resolve the disks and detect planets responsible for the disk morphology. In this paper, we study the F-type star HIP 67497 and present a first-order modelization of the disk in order to derive its main properties. Methods: We used the near-infrared integral field spectrograph (IFS) and dual-band imager IRDIS of VLT/SPHERE to obtain angular-differential imaging observations of the circumstellar environnement of HIP 67497. We removed the stellar halo with PCA and TLOCI algorithms. The disk emission was modeled with the GRaTeR code. Results: We resolve a ring-like structure that extends up to 450 mas ( 50 au) from the star in the IRDIS and IFS data. It is best reproduced by models of a non-eccentric ring with an inclination of 80 ± 1°, a position angle of -93 ± 1°, and a semi-major axis of 59 ± 3 au. We also detect an additional, but fainter, arc-like structure with a larger extension (0.65 arcsec) South of the ring that we model as a second belt of debris at 130 au. We detect ten candidate companions at separations ≥1''. We estimate the mass of putative perturbers responsible for the disk morphology and compare this to our detection limits. Additional data are needed to find those perturbers, and to relate our images to large-scale structures seen with HST/STIS. Based on observations made with ESO Telescopes at the Paranal Observatory under programme ID 097.C-0060(A)This work is based on data products produced at the SPHERE Data Center hosted at OSUG/IPAG, Grenoble.

  9. Aqueous alteration on main-belt asteroids

    Science.gov (United States)

    Fornasier, S.; Lantz, C.; Barucci, M.; Lazzarin, M.

    2014-07-01

    The study of aqueous alteration is particularly important for unraveling the processes occurring during the earliest times in Solar System history, as it can give information both on the thermal processes and on the localization of water sources in the asteroid belt, and for the associated astrobiological implications. The aqueous alteration process produces the low temperature (< 320 K) chemical alteration of materials by liquid water which acts as a solvent and produces materials like phyllosilicates, sulphates, oxides, carbonates, and hydroxides. This means that liquid water was present in the primordial asteroids, produced by the melting of water ice by heating sources, very probably by ^{26}Al decay. Hydrated minerals have been found mainly on Mars surface, on primitive main-belt asteroids (C, G, B, F, and P-type, following the classification scheme by Tholen, 1984) and possibly also on few transneptunian objects. Reflectance spectroscopy of aqueous altered asteroids shows absorption features in the 0.6-0.9 and 2.5-3.5-micron regions, which are diagnostic of, or associated with, hydrated minerals. In this work, we investigate the aqueous alteration process on a large sample of 600 visible spectra of C-complex asteroids available in the literature. We analyzed all these spectra in a similar way to characterize the absorption-band parameters (band center, depth, and width) and spectral slope, and to look for possible correlations between the aqueous alteration process and the asteroids taxonomic classes, orbital elements, heliocentric distances, albedo, and sizes. We find that 4.6 % of P, 7.7 % of F, 9.8 % of B, 50.5 % of C, and 100 % of the G-type asteroids have absorption bands in the visible region due to hydrated silicates. Our analysis shows that the aqueous alteration sequence starts from the P-type objects, practically unaltered, and increases through the P → F → B → C → G asteroids, these last being widely aqueously altered, strengthening thus

  10. Two new basaltic asteroids in the Outer Main Belt

    CERN Document Server

    Duffard, R

    2007-01-01

    The identification of other basaltic objects in the asteroid belt is mandatory to explain the diversity in the collection of basaltic meteorites. This diversity requires more than one differentiated parent body, a fact that is consistent with the diversity of differentiated parent bodies implied by the iron meteorites. Based on a list of previously identified candidate basaltic (V-type) asteroids, two asteroids in the outer main belt, (7472) Kumakiri and (10537) 1991 RY16, were spectroscopically observed during an observational run in Calar Alto Observatory, Spain. We confirm the V-type character of these two asteroids that, together with (1459) Magnya, become the only known traces of basaltic found in the outer main belt up to now. We also demonstrate that the searching for candidate V-type asteroids using a photometric survey, like the Sloan Digital Sky Survey, produces reliable results.

  11. Gravity inferred subsurface structure of Gadwal Schist belt, Andhra Pradesh

    Indian Academy of Sciences (India)

    G Ramadass; I B Ramaprasada Rao; N Srinivasulu

    2001-03-01

    Detailed gravity data collected across the Gadwal schist belt in the state of Andhra Pradesh show an 8.4 mgal residual gravity anomaly associated with meta-sediments/volcanics of the linear NNW-SSE trending schist belt that shows metamorphism from green schist to amphibolite facies. This schist belt is flanked on either side by the peninsular gneissic complex. The elevation and slab Bouguer corrected residual gravity profile data were interpreted using 2-D prism models. The results indicate a synformal structure having a width of 1.8 km at the surface, tapering at a depth of about 2.6 km with a positive density contrast of 0.15 gm/cc with respect to the surrounding peninsular gneissic complex.

  12. The Living with a Star Radiation Belt Storm Probes

    Science.gov (United States)

    Sibeck, D. G.; Mauk, B. H.; Grebowsky, J. M.; Fox, N. J.

    2007-01-01

    The goal of NASA's Living With a Star Radiation Belt Storm Probe mission is to understand, ideally to the point of predictability, how populations of relativistic electrons and ions in space form or change in response to the variable inputs of energy from the Sun. The investigations selected for this 2-spacecraft mission scheduled for launch in early 2012 address this task by making extensive observations of the plasma waves, thermal, ring current, and relativistic particle populations, and DC electric and magnetic fields within the Earth's inner and outer radiation belts. We first describe the current mission concept within the scope of NASA's strategic plan and the Vision for Exploration, and then consider how its observations will be used to define and quantify the processes that accelerate, transport, and remove particles in the Earth's radiation belts.

  13. Recent Developments in the Radiation Belt Environment Model

    Science.gov (United States)

    Fok, M.-C.; Glocer, A.; Zheng, Q.; Horne, R. B.; Meredith, N. P.; Albert, J. M.; Nagai, T.

    2010-01-01

    The fluxes of energetic particles in the radiation belts are found to be strongly controlled by the solar wind conditions. In order to understand and predict the radiation particle intensities, we have developed a physics-based Radiation Belt Environment (RBE) model that considers the influences from the solar wind, ring current and plasmasphere. Recently, an improved calculation of wave-particle interactions has been incorporated. In particular, the model now includes cross diffusion in energy and pitch-angle. We find that the exclusion of cross diffusion could cause significant overestimation of electron flux enhancement during storm recovery. The RBE model is also connected to MHD fields so that the response of the radiation belts to fast variations in the global magnetosphere can be studied.Weare able to reproduce the rapid flux increase during a substorm dipolarization on 4 September 2008. The timing is much shorter than the time scale of wave associated acceleration.

  14. Radiation Belt Environment Model: Application to Space Weather and Beyond

    Science.gov (United States)

    Fok, Mei-Ching H.

    2011-01-01

    Understanding the dynamics and variability of the radiation belts are of great scientific and space weather significance. A physics-based Radiation Belt Environment (RBE) model has been developed to simulate and predict the radiation particle intensities. The RBE model considers the influences from the solar wind, ring current and plasmasphere. It takes into account the particle drift in realistic, time-varying magnetic and electric field, and includes diffusive effects of wave-particle interactions with various wave modes in the magnetosphere. The RBE model has been used to perform event studies and real-time prediction of energetic electron fluxes. In this talk, we will describe the RBE model equation, inputs and capabilities. Recent advancement in space weather application and artificial radiation belt study will be discussed as well.

  15. Relativistic surfatron process for Landau resonant electrons in radiation belts

    CERN Document Server

    Osmane, A

    2014-01-01

    Recent theoretical studies of the nonlinear wave-particle interactions for relativistic particles have shown that Landau resonant orbits could be efficiently accelerated along the mean background magnetic field for propagation angles $\\theta$ in close proximity to a critical propagation $\\theta_\\textrm{c}$ associated with a Hopf--Hopf bifurcation condition. In this report, we extend previous studies to reach greater modeling capacities for the study of electrons in radiation belts by including longitudinal wave effects and inhomogeneous magnetic fields. We find that even though both effects can limit the surfatron acceleration of electrons in radiation belts, gains in energy of the order of 100 keV, taking place on the order of ten milliseconds, are sufficiently strong for the mechanism to be relevant to radiation belt dynamics.

  16. Formation and decay of the inner electron radiation belt

    Science.gov (United States)

    Su, Y. J.; Selesnick, R.

    2016-12-01

    The inner electron radiation belt was found, early in the space age, to be highly variable with rapid injections followed by slower decay. Highly structured energy spectra were also observed (now known in energy-time spectrograms as "zebra stripes"). Inner belt formation was explained by inward diffusion. However, even the fastest diffusion is expected to require a period of many days, while observations show frequent rapid injections across the entire inner belt (as low as L=1.2) during periods of injections, slow decay, and structured energy spectra, as observed from Van Allen Probes for electrons with energies of 100-400 keV, by the action of large-scale electric fields. In addition, a case study of a non-diffusive fast injection event that occurred on March 17, 2013, is simulated by a test particle code which demonstrates the sensitivity of electron intensity to the selected electric field model.

  17. Jovian Early Bombardment: planetesimal erosion in the inner asteroid belt

    CERN Document Server

    Turrini, Diego; Magni, Gianfranco

    2012-01-01

    The asteroid belt is an open window on the history of the Solar System, as it preserves records of both its formation process and its secular evolution. The progenitors of the present-day asteroids formed in the Solar Nebula almost contemporary to the giant planets. The actual process producing the first generation of asteroids is uncertain, strongly depending on the physical characteristics of the Solar Nebula, and the different scenarios produce very diverse initial size-frequency distributions. In this work we investigate the implications of the formation of Jupiter, plausibly the first giant planet to form, on the evolution of the primordial asteroid belt. The formation of Jupiter triggered a short but intense period of primordial bombardment, previously unaccounted for, which caused an early phase of enhanced collisional evolution in the asteroid belt. Our results indicate that this Jovian Early Bombardment caused the erosion or the disruption of bodies smaller than a threshold size, which strongly depen...

  18. The effects of seat belt legislation on road traffic injuries.

    Science.gov (United States)

    Trinca, G W; Dooley, B J

    1977-04-01

    The compulsory wearing of seat belts, first introduced in the world in Victoria in 1970, has effectively reduced the number of deaths and injuries by approximately one-third for car occupants involved in motor vehicle crashes. Initially, the legislation did not apply to children under the age of eight years, but in 1975 a further law was introduced banning children from the front seat of any vehicle unless properly harnessed. Seat belts offer the best protection for front seat drivers and passengers involved in frontal impacts, but offer less protection to the recipient of a side impact. Ten per cent of car occupants admitted to hospital after a frontal impact show injuries, mostly minor, directly attibutable to the wearing of seat belts.

  19. Regional Fault Systems of Qaidam Basin and Adjacent Orogenic Belts

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The purpose of this paper is to analyze the regional fault systems of Qaidam basin and adjacent orogenic belts. Field investigation and seismic interpretation indicate that five regional fault systems occurred in the Qaidam and adjacent mountain belts, controlling the development and evolution of the Qaidam basin. These fault systems are: (1)north Qaidam-Qilian Mountain fault system; (2) south Qaidam-East Kunlun Mountain fault system; (3)Altun strike-slip fault system; (4)Elashan strike-slip fault system, and (5) Gansen-Xiaochaidan fault system. It is indicated that the fault systems controlled the orientation of the Qaidam basin, the formation and distribution of secondary faults within the basin,the migration of depocenters and the distribution of hydrocarbon accumulation belt.

  20. RATIONALE FOR CENTERING CAPACITY OF REDISIGNED BELT CONVEYOR DRUMS

    Directory of Open Access Journals (Sweden)

    V. V. Suglobov

    2016-02-01

    Full Text Available Purpose. In the study is necessary: 1 to justify aligning drums of a new design of belt conveyors; 2 to develop a method for calculating and determining the rational design parameters of drums depending on the technical parameters of the conveyor belt (the length of the conveyor, belt width, the performance of the conveyor, the diameter of the drive and tension drums, etc.; 3 to carry out pilot studies of efficiency conveyor belt in a production environment in order to determine the magnitude of dynamic loads and a comparative evaluation of the effectiveness of the centering ability of conventional and new designs of drums. Methodology. To substantiate the effectiveness of the centering ability of the drums of a new design by the authors developed a mathematical model of interaction of the tape with the drum. Mathematical simulation of tape reels with new design comes to drawing up a differential equation of the belt based on the dynamic component and restoring force. This model allowed us to estimate the movement of the tape in the transverse direction based on the calculated additional dynamic loads and forces on the investigated centering a conveyor belt with given specifications. For the first time the technique of calculating and determining the rational parameters of the drums, which allows determining the design parameters of the centering portions, depending on the mechanical properties and geometric parameters of the tape. Findings. With the help of mathematical modeling the scientifically substantiated effect of centering the ability of the new design of the drum, which ensures stable tape running along the longitudinal axis of the conveyor. The authors made the following conclusions: 1 the mathematical model of interaction with the new belt design of the drum, which allowed to describe the belt in the transverse direction in view of additional dynamic loads and renewable power was developed; 2 the method of calculation and

  1. The Belt voice: Acoustical measurements and esthetic correlates

    Science.gov (United States)

    Bounous, Barry Urban

    This dissertation explores the esthetic attributes of the Belt voice through spectral acoustical analysis. The process of understanding the nature and safe practice of Belt is just beginning, whereas the understanding of classical singing is well established. The unique nature of the Belt sound provides difficulties for voice teachers attempting to evaluate the quality and appropriateness of a particular sound or performance. This study attempts to provide answers to the question "does Belt conform to a set of measurable esthetic standards?" In answering this question, this paper expands on a previous study of the esthetic attributes of the classical baritone voice (see "Vocal Beauty", NATS Journal 51,1) which also drew some tentative conclusions about the Belt voice but which had an inadequate sample pool of subjects from which to draw. Further, this study demonstrates that it is possible to scientifically investigate the realm of musical esthetics in the singing voice. It is possible to go beyond the "a trained voice compared to an untrained voice" paradigm when evaluating quantitative vocal parameters and actually investigate what truly beautiful voices do. There are functions of sound energy (measured in dB) transference which may affect the nervous system in predictable ways and which can be measured and associated with esthetics. This study does not show consistency in measurements for absolute beauty (taste) even among belt teachers and researchers but does show some markers with varying degrees of importance which may point to a difference between our cognitive learned response to singing and our emotional, more visceral response to sounds. The markers which are significant in determining vocal beauty are: (1) Vibrancy-Characteristics of vibrato including speed, width, and consistency (low variability). (2) Spectral makeup-Ratio of partial strength above the fundamental to the fundamental. (3) Activity of the voice-The quantity of energy being produced. (4

  2. Photometry and Lightcurve Analysis of 7 Main-Belt Asteroids

    Science.gov (United States)

    Violante, Renata; Leake, M. A.

    2013-01-01

    We report the synodic periods and lightcurves for three main-belt asteroids and provide lightcurves for four other main-belt asteroids. 676 Melitta has a period of 8.35 ± 0.05 hours, with an amplitude of 0.056 ± 0.026 magnitude; 688 Melanie has a period of 16.10 ± 0.05 hours, and an amplitude of 0.091 ± 0.019 magnitude; 1677 Tycho Brahe has a period of 3.89 ± 0.06 hours, and an amplitude of 0.564 ± 0.011 magnitude.

  3. Detection of methane on Kuiper Belt Object (50000) Quaoar

    CERN Document Server

    Schaller, E L

    2007-01-01

    The near-infrared spectrum of (50000) Quaoar obtained at the Keck Observatory shows distinct absorption features of crystalline water ice, solid methane and ethane, and possibly other higher order hydrocarbons. Quaoar is only the fifth Kuiper belt object on which volatile ices have been detected. The small amount of methane on an otherwise water ice dominated surface suggests that Quaoar is a transition object between the dominant volatile-poor small Kuiper belt objects (KBOs) and the few volatile-rich large KBOs such as Pluto and Eris.

  4. A Spectroscopically Unique Main Belt Asteroid: 10537 (1991 RY16)

    CERN Document Server

    Moskovitz, Nicholas A; Jedicke, Robert; Willman, Mark; Haghighipour, Nader; Bus, Schelte J; Gaidos, Eric

    2008-01-01

    We present visible and near-infrared reflectance spectra and interpreted surface mineralogy for asteroid 10537 (1991 RY16). The spectrum of this object is without precedent amongst the Main Belt asteroids. A unique absorption band centered at 0.63 microns could be attributed to one of several mineralogies. Pronounced 1- and 2-micron absorption bands suggest that the composition of 10537 is a mixture of pyroxenes and olivine and that it originated from a parent body that was partially or fully differentiated. The closest available analog is the large Main Belt asteroid 349 Dembowska but 10537 may be an isolated fragment from a completely eroded parent body.

  5. Seat belt trauma: pectoralis muscle rupture and delayed mesh repair.

    Science.gov (United States)

    Harvey, Kyle P; Adair, James D; Ali, M Azhar

    2008-03-01

    To our knowledge, this is the first reported case of a seat belt-related rupture of the pectoralis major muscle and its successful delayed repair using mesh. We report a case of a 34-year-old white man who sustained a right pectoralis major muscle rupture from a seat belt during a motor vehicle crash. The patient presented to us 2 years after the injury. We introduce a technique using mesh that results in a successful repair of a cosmetically disfiguring chest wall defect.

  6. Active Asteroids: Main-Belt Comets and Disrupted Asteroids

    CERN Document Server

    Hsieh, Henry H

    2015-01-01

    The study of active asteroids has attracted a great deal of interest in recent years since the recognition of main-belt comets (which orbit in the main asteroid belt, but exhibit comet-like activity due to the sublimation of volatile ices) as a new class of comets in 2006, and the discovery of the first disrupted asteroids (which, unlike MBCs, exhibit comet-like activity due to a physical disruption such as an impact or rotational destabilization, not sublimation) in 2010. In this paper, I will briefly discuss key areas of interest in the study of active asteroids.

  7. Intestinal stricture following seat belt injury in children.

    Science.gov (United States)

    Lynch, J M; Albanese, C T; Meza, M P; Wiener, E S

    1996-10-01

    The most commonly reported intestinal injury from seat belts in children is perforation. A rarely reported late sequela following this type of injury is posttraumatic intestinal stricture (PTIS). A review of the literature reveals a common clinical pattern of presentation in children and adults but an apparent difference in the pathophysiologic mechanism between the pediatric and adult patient. Recently, we treated two children with PTIS. Each case is discussed, and a pathophysiological mechanism for this injury in children is proposed. Recommendations are made for the evaluation and treatment of these uncommon complications of seat belt-related blunt intestinal injury.

  8. Traffic restrictions due to wind on the Fehmarn Belt bridge

    DEFF Research Database (Denmark)

    Dellwik, E.; Mann, Jakob; Rosenhagen, G.

    2006-01-01

    This report documents the calculations carried out in order to estimate the wind climate at the site where the Fehmarn Belt bridge is planned. Further, an estimate of how often and for how long traffic restrictions will be enforced according to statedcriteria (sec. 3.2) is given. This estimate...... is given both as a total percentage of time and as a mean distribution of restrictions over the year. We perform the same analysis for the Øresund and the Great Belt bridge and compare the result with the actualfractions. Only during the last year of operation of the Øresund bridge the criteria...

  9. Nonsanction seat belt law enforcement: a modern day tale of two cities.

    Science.gov (United States)

    Hunter, W W; Stewart, J R; Stutts, J C; Marchetti, L M

    1993-10-01

    This paper describes the implementation and evaluation of a nonsanction seat belt law enforcement program in two experimental communities of contrasting size in a state with a mandatory belt law. The main ingredients of the program were seat belt "salutes," public information and education, and limited use of inexpensive economic incentives. Driver shoulder belt use data collected before, during, and after the experimental programs, compared to similar data collected in a comparison community, showed the approach to be effective. While standard seat belt enforcement activities without incentives have been shown to be effective, many police departments, especially in smaller communities, are reluctant to make wholesale increases in seat belt citations. Although requiring some additional level of manpower and resources, a nonsanction approach to seat belt law enforcement can provide an alternate way of increasing belt use in these communities.

  10. Explaining the dynamics of the ultra-relativistic third Van Allen radiation belt

    OpenAIRE

    Mann, Ian R.; Ozeke, L. G.; Murphy, Kyle R; Clauderpierre, S. G.; Turner, D. L.; Baker, D. N.; Rae, I. J.; Kale, A; Milling, David; Boyd, A. J.; Spence, H. E.; Reeves, G. D.; H. J. Singer; Dimitrakoudis, S.; Daglis, I. A.

    2016-01-01

    Since the discovery of the Van Allen radiation belts over 50 years ago, an explanation for their complete dynamics has remained elusive. Especially challenging is understanding the recently discovered ultra-relativistic third electron radiation belt. Current theory asserts that loss in the heart of the outer belt, essential to the formation of the third belt, must be controlled by high-frequency plasma wave–particle scattering into the atmosphere, via whistler mode chorus, plasmaspheric hiss,...

  11. Safety belt promotion at community swimming pools :effects of policy, rewards, prompts, and education

    OpenAIRE

    Gilmore, Michael Richard

    1990-01-01

    Data on safety belt use were collected at two swimming pools over three consecutive summers. The impact of several variables upon safety belt use was examined. First, an Intervention Program (IP) was designed, comprised of Promotional, Reward, and Feedback components. Second, an Awareness/Education (AE) strategy was introduced to children enrolled in swim lessons. Third, belt use was examined before and after a mandatory safety belt use law (BUL) was enacted in Virginia. The moderating ef...

  12. Anterior inferior iliac spine fracture: Another component of seat belt syndrome?

    Directory of Open Access Journals (Sweden)

    Paisal HUSSIN

    2013-04-01

    Full Text Available Seat belt syndrome occurs when seat belts are used improperly, and it is a cause of significant morbidity and mortality. The spectrum of seat belt syndrome includes spinal, intra-abdominal and vascular injury. Here, we report the case of anterior inferior iliac spine avulsion fracture in association with seat belt injuries in a 24-year old man involved in a head on motor vehicle collision. 

  13. 75 FR 4509 - Uniform Criteria for State Observational Surveys of Seat Belt Use

    Science.gov (United States)

    2010-01-28

    ... Observational Surveys of Seat Belt Use AGENCY: National Highway Traffic Safety Administration (NHTSA... amendments to the regulations establishing the criteria for designing and conducting State seat belt use... seat belt use rates to NHTSA. NHTSA proposes these amendments so that future surveys will give...

  14. 23 CFR 1240.13 - Determination of national average seat belt use rate.

    Science.gov (United States)

    2010-04-01

    ... 23 Highways 1 2010-04-01 2010-04-01 false Determination of national average seat belt use rate... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION GUIDELINES SAFETY INCENTIVE GRANTS FOR USE OF SEAT BELTS-ALLOCATIONS BASED ON SEAT BELT USE RATES Determination of Allocations § 1240.13 Determination of national...

  15. Seat Belt Education Program--A Model for Public Health Settings.

    Science.gov (United States)

    Saunders, Stephen; Pine, Jeffrey

    1986-01-01

    The purpose of the study was to determine whether a brief seat belt group educational intervention could be incorporated into an existing public health program and result in increased use of seat belts. Seat belt use increased from 4.9 to 12.6 percent among 268 low-income mothers during the study. (Author/CH)

  16. 48 CFR 1252.223-73 - Seat belt use policies and programs.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Seat belt use policies and....223-73 Seat belt use policies and programs. As prescribed in (TAR) 48 CFR 1223.7000(c), insert the following clause: Seat Belt Use Policies and Programs (APR 2005) In accordance with Executive Order...

  17. 49 CFR 173.166 - Air bag inflators, air bag modules and seat-belt pretensioners.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Air bag inflators, air bag modules and seat-belt... Than Class 1 and Class 7 § 173.166 Air bag inflators, air bag modules and seat-belt pretensioners. (a... an inflatable bag assembly. A seat-belt pre-tensioner contains similar hazardous materials and...

  18. Seat Belt Law Experience in Four Foreign Countries Compared to the United States.

    Science.gov (United States)

    Campbell, B. J.; Campbell, Frances A.

    This report examines the process of enacting laws requiring the use of seat belts in the United States. It assesses these laws against the perspective of benefits realized from such mandates in other nations. Chapter one is an introduction; chapter two provides background on seat belt installation in U.S. vehicles, introduction of belt use laws,…

  19. 30 CFR 56.14130 - Roll-over protective structures (ROPS) and seat belts.

    Science.gov (United States)

    2010-07-01

    ... protective structures (ROPS) and seat belts. (a) Equipment included. Roll-over protective structures (ROPS) and seat belts shall be installed on— (1) Crawler tractors and crawler loaders; (2) Graders; (3) Wheel... October 24, 1988, that is equipped with ROPS and seat belts that meet the installation and...

  20. 76 FR 36890 - Clarification of Prior Interpretations of the Seat Belt and Seating Requirements for General...

    Science.gov (United States)

    2011-06-23

    ... Federal Aviation Administration 14 CFR Part 91 Clarification of Prior Interpretations of the Seat Belt and... clarify prior interpretations of the seat belt and seating requirements of 14 CFR 91.107(a)(3). These... clarification states that the use of a seat belt and/or seat by more than one occupant is appropriate only...

  1. 77 FR 20550 - Uniform Criteria for State Observational Surveys of Seat Belt Use

    Science.gov (United States)

    2012-04-05

    ... State Observational Surveys of Seat Belt Use AGENCY: National Highway Traffic Safety Administration... implementation date for use of the revised uniform criteria for State Observational Surveys of Seat Belt Use... Observational Surveys of Seat Belt Use.'' 76 FR 18042. That final rule amended the regulation...

  2. 23 CFR Appendix D to Part 1240 - Determination of National Average Seat Belt Use Rate

    Science.gov (United States)

    2010-04-01

    ... 23 Highways 1 2010-04-01 2010-04-01 false Determination of National Average Seat Belt Use Rate D... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION GUIDELINES SAFETY INCENTIVE GRANTS FOR USE OF SEAT BELTS-ALLOCATIONS BASED ON SEAT BELT USE RATES Pt. 1240, App. D Appendix D to Part 1240—Determination of National...

  3. 77 FR 30885 - Clarification of Prior Interpretations of the Seat Belt and Seating Requirements for General...

    Science.gov (United States)

    2012-05-24

    ... Administration 14 CFR Part 91 [Docket No. FAA-2011-0628] Clarification of Prior Interpretations of the Seat Belt... interpretations of FAA's seat belt and seating requirements. These prior interpretations state that the shared use of a single restraint may be permissible. This clarification states that the use of a seat belt...

  4. Using naturalistic driving data to identify variables associated with infrequent, occasional, and consistent seat belt use.

    Science.gov (United States)

    Reagan, Ian J; McClafferty, Julie A; Berlin, Sharon P; Hankey, Jonathan M

    2013-01-01

    Seat belt use is one of the most effective countermeasures to reduce traffic fatalities and injuries. The success of efforts to increase use is measured by road side observations and self-report questionnaires. These methods have shortcomings, with the former requiring a binary point estimate and the latter being subjective. The 100-car naturalistic driving study presented a unique opportunity to study seat belt use in that seat belt status was known for every trip each driver made during a 12-month period. Drivers were grouped into infrequent, occasional, or consistent seat belt users based on the frequency of belt use. Analyses were then completed to assess if these groups differed on several measures including personality, demographics, self-reported driving style variables as well as measures from the 100-car study instrumentation suite (average trip speed, trips per day). In addition, detailed analyses of the occasional belt user group were completed to identify factors that were predictive of occasional belt users wearing their belts. The analyses indicated that consistent seat belt users took fewer trips per day, and that increased average trip speed was associated with increased belt use among occasional belt users. The results of this project may help focus messaging efforts to convert occasional and inconsistent seat belt users to consistent users.

  5. The use of seat belts and contributing factors : an international comparison.

    NARCIS (Netherlands)

    Mäkinen, T. Wittink, R.D. & Hagenzieker, M.P.

    1991-01-01

    The purpose of this study was to define factors that contribute to the use or non-use of seat belts. Legislation prescribing compulsory seat belt usage is one of the most important factors. Promotion of the use of seat belts without this legislation is very difficult and time-consuming. So far, the

  6. PROPOSALS ON IMPROVING THE EXCAVATION, TRANSPORT AND COAL DEPOSIT, USING THE RUBBER CONVEYOR BELT

    Directory of Open Access Journals (Sweden)

    Nicoleta-Maria MIHUT

    2016-05-01

    Full Text Available In this work we make a study of the improvement methods of quantity of material transported by conveyor belt. Determination of discharge of solids entail establish of the parameters of the conveyor belt. As a result, we determine the belt speed who provide maximum discharge of solids materials.

  7. The use of seat belts and contributing factors : an international comparison.

    NARCIS (Netherlands)

    Mäkinen, T. Wittink, R.D. & Hagenzieker, M.P.

    1991-01-01

    The purpose of this study was to define factors that contribute to the use or non-use of seat belts. Legislation prescribing compulsory seat belt usage is one of the most important factors. Promotion of the use of seat belts without this legislation is very difficult and time-consuming. So far, the

  8. Structure of Possible Long-lived Asteroid Belts

    CERN Document Server

    Evans, N W

    2002-01-01

    High resolution simulations are used to map out the detailed structure of two long-lived stable belts of asteroid orbits in the inner Solar system. The Vulcanoid belt extends from 0.09 to 0.20 astronomical units (au), though with a gaps at 0.15 and 0.18 au corresponding to de-stabilising mean motion resonances with Mercury and Venus. As collisional evolution proceeds slower at larger heliocentric distances, kilometre-sized or larger Vulcanoids are most likely to be found in the region between 0.16 and 0.18 au. The optimum location in which to search for Vulcanoids is at geocentric ecliptic longitudes roughly between 9 and 10 degrees. Dynamically speaking, the Earth-Mars belt between 1.08-1.28 au is an extremely stable repository for asteroids on nearly circular orbits. It is interrupted at 1.21 au due to the 3:4 commensurability with the Earth, while secular resonances with Saturn are troublesome beyond 1.17 au. These detailed maps of the fine structure of the belts can be used to plan search methodologies. S...

  9. Chaos in Mean Motion Resonances of the Kuiper Belt

    CERN Document Server

    Franklin, Fred

    2014-01-01

    In this paper on mean motion resonances in the Kuiper belt we consider effects on resonant bodies captured in an earlier migration by determining levels of chaos as a function of eccentricity, e, at the most stable orbital configuration. We find the the maximum observed e's at resonance very closely correspond to orbits with Lyapunov times ~ 1000 orbital periods of Neptune--much the same number as applies in the asteroid belt with Neptune's period replaced by Jupiter's. The fact that this number caps the e's of markedly chaotic but still existing bodies, implies that the great majority of escapes at equal and larger e's have already occurred. Yet escapes must continue at some level if the small population in the outermost belt is to be maintained because typical lifetimes of bodies there are only ~ 1/10 of the solar system's age. A study of stability at resonance also reinforces the claim that the post-migration boundary of the inner Kuiper belt lies near 34 AU and that the primordial, or pre-migration, outer...

  10. Influence of the Gould Belt on Interstellar Extinction

    CERN Document Server

    Gontcharov, George

    2016-01-01

    A new analytical 3D model of interstellar extinction within 500 pc of the Sun as a function of the Galactic spherical coordinates is suggested. This model is physically more justified than the widely used Arenou model, since it takes into account the presence of absorbing matter both in the layer along the equatorial Galactic plane and in the Gould Belt. The extinction in the equatorial layer varies as the sine of the Galactic longitude and in the Gould Belt as the sine of twice the longitude in the Belt plane. The extinction across the layers varies according to a barometric law. It has been found that the absorbing layers intersect at an angle of 17 deg and that the Sun is located near the axial plane of the absorbing layer of the Gould Belt and is probably several parsecs below the axial plane of the equatorial absorbing layer but above the Galactic plane. The model has been tested using the extinction of real stars from three catalogs.

  11. Structural appraisal of the Gadag schist belt from gravity investigations

    Indian Academy of Sciences (India)

    G Ramadass; D Himabindu; N Srinivasulu

    2003-12-01

    Semi-detailed gravity investigations were carried out over an area of approximately 2750 sq km with maximum N-S and E-W extents of 55 and 50km respectively in the Gadag region in the Dharwar craton with a view to obtain a clearer perception of the structural configuration of the region. From qualitative analysis of the gravity data, several tectonic features are inferred: the high density Gadag schist belt is characterized by a gravity high and occurs in two discontinuous segments — the main N-S trending segment, and its thinner NW-SE trending extension, the two separated by a NE-SW trending deep seated fault. While the N-S trend of the Gadag schist belt is bounded on its east by the NW-SE trending Chitradurga thrust fault and on its west by another major NNW-SSE trending fault, the NW-SE extension is likewise bounded by two other NW-SE major faults. Quantitative evaluation from forward modeling/inversion of five profiles in the region, assuming a density contrast of 0.29 gm/cc of the anomalous schistose body with the gneissic host rocks indicated a synclinal structure plunging to the southeast along its axis for the Gadag schist belt. The maximum width and depth from surface of the schist belt are 22km and 5.6km respectively.

  12. 29 CFR 1926.104 - Safety belts, lifelines, and lanyards.

    Science.gov (United States)

    2010-07-01

    ... be subjected to cutting or abrasion, shall be a minimum of 7/8-inch wire core manila rope. For all... strength of 5,400 pounds, shall be used. (d) Safety belt lanyard shall be a minimum of 1/2-inch nylon, or...

  13. CDC Vital Signs: Adult Seat Belt Use in the US

    Science.gov (United States)

    ... up in a seat belt, booster seat, or car seat, whichever is appropriate.* Have all children age 12 and under sit in the back seat. Never seat a child in front of an air bag. Place children in the middle of the back ...

  14. Radiation Belt Storm Probes (RBSP) Payload Safety Introduction Briefing

    Science.gov (United States)

    Loftin, Chuck; Lampert, Dianna; Herrburger, Eric; Smith, Clay; Hill, Stuart; VonMehlem, Judi

    2008-01-01

    Mission of the Geospace Radiation Belt Storm Probes (RBSP) is: Gain s cientific understanding (to the point of predictability) of how populations of relativistic electrons and ions in space form or change in response to changes in solar activity and the solar wind.

  15. Wave acceleration of electrons in the Van Allen radiation belts.

    Science.gov (United States)

    Horne, Richard B; Thorne, Richard M; Shprits, Yuri Y; Meredith, Nigel P; Glauert, Sarah A; Smith, Andy J; Kanekal, Shrikanth G; Baker, Daniel N; Engebretson, Mark J; Posch, Jennifer L; Spasojevic, Maria; Inan, Umran S; Pickett, Jolene S; Decreau, Pierrette M E

    2005-09-08

    The Van Allen radiation belts are two regions encircling the Earth in which energetic charged particles are trapped inside the Earth's magnetic field. Their properties vary according to solar activity and they represent a hazard to satellites and humans in space. An important challenge has been to explain how the charged particles within these belts are accelerated to very high energies of several million electron volts. Here we show, on the basis of the analysis of a rare event where the outer radiation belt was depleted and then re-formed closer to the Earth, that the long established theory of acceleration by radial diffusion is inadequate; the electrons are accelerated more effectively by electromagnetic waves at frequencies of a few kilohertz. Wave acceleration can increase the electron flux by more than three orders of magnitude over the observed timescale of one to two days, more than sufficient to explain the new radiation belt. Wave acceleration could also be important for Jupiter, Saturn and other astrophysical objects with magnetic fields.

  16. Dynamics of the low altitude secondary proton radiation belt.

    Science.gov (United States)

    Gusev, A A; Kohno, T; Spjeldvik, W N; Martin, I M; Pugacheva, G I; Turtelli, A

    1998-01-01

    At the interface between the upper atmosphere and the radiation belt region, there exists a secondary radiation belt consisting mainly of energetic ions that have become neutralized in the ring current and the main radiation belt and then re-ionized by collisions in the inner exosphere. The time history of the proton fluxes in the 0.64-35 MeV energy range was traced in the equatorial region beneath the main radiation belts during the three year period from 21 February 1984 to 26 March 1987 using data obtained with the HEP experiment on board the Japanese OHZORA satellite. During most of this period a fairly small proton flux of -1.2 cm-2 S-1 sr-1 was detected on geomagnetic field lines in the range 1.05 < L < 1.15. We report a few surprisingly deep and rapid flux decreases (flux reduction by typically two orders of magnitude). These flux decreases were also long in duration (lasting up to three months). We also registered abrupt flux increases where the magnitude of the proton flux enhancements could reach three orders of magnitude with an enhancement duration of 1-3 days. Possible reasons for these unexpected phenomena are discussed.

  17. 1991 National campaign to increase safety belt usage.

    NARCIS (Netherlands)

    National Highway Traffic Safety Administration NHTSA

    1992-01-01

    The central theme of this paper is the national campaign of the USA to be conducted in 1991 and 1992, in order to reach the goal of 70 percent safety belt usage by 1992. Among other things, it is shown that visible enforcement of existing laws offers the greatest potential for achieving this goal. F

  18. Determination of Flutter Derivatives for the Great Belt Bridge

    DEFF Research Database (Denmark)

    Poulsen, Niels Kjølstad; Damsgaard, Aage; Reinhold, Thim A.

    1992-01-01

    A new method which combines control theory and system identification techniques has been used to extract flutter derivatives from section model tests for the Great Belt East Bridge. Tests were conducted by exciting the section model simultaneously in vertical and torsional modes of vibration. Tests...

  19. Knowledge, attitude and use of seat belt among commercial drivers ...

    African Journals Online (AJOL)

    The effectiveness of seat belt usage in reducing the severity of the sequelae of road traffic accidents is widely known. ... Each correct response to the knowledge questions was scored one mark and wrong response or non-response was ...

  20. On the Dynamics of Resonant Kuiper Belt Objects

    CERN Document Server

    Jiang, I G; Jiang, Ing-Guey; Yeh, Li-Chin

    2007-01-01

    We propose a new mechanism of drag-induced resonant capture, which can explain the resonant Kuiper Belt Objects in a natural way. A review and comparison with the traditional mechanism of sweeping capture by the migrating Neptune will be given.

  1. Effective Conveyor Belt Inspection for Improved Mining Productivity

    Energy Technology Data Exchange (ETDEWEB)

    Chris Fromme

    2006-06-01

    This document details progress on the project entitled ''Effective Conveyor Belt Inspection for Improved Mining Productivity'' during the period from November 15, 2004 to May 14, 2004. Highlights include fabrication of an improved LED lightbar, fabrication of a line-scan sensor head for the Smart-Camera based prototype, and development of prototype vulcanized splice detection algorithms.

  2. Radiation Belt Storm Probes—Observatory and Environments

    Science.gov (United States)

    Kirby, Karen; Artis, David; Bushman, Stewart; Butler, Michael; Conde, Rich; Cooper, Stan; Fretz, Kristen; Herrmann, Carl; Hill, Adrian; Kelley, Jeff; Maurer, Richard; Nichols, Richard; Ottman, Geffrey; Reid, Mark; Rogers, Gabe; Srinivasan, Dipak; Troll, John; Williams, Bruce

    2013-11-01

    The National Aeronautics and Space Administration's (NASA's) Radiation Belt Storm Probe (RBSP) is an Earth-orbiting mission that launched August 30, 2012, and is the latest science mission in NASA's Living with a Star Program. The RBSP mission will investigate, characterize and understand the physical dynamics of the radiation belts, as well as the influence of the Sun on the Earth's environment, by measuring particles, electric and magnetic fields and waves that comprise geospace. The mission is composed of two identically instrumented spinning observatories in an elliptical orbit around earth with 600 km perigee, 30,000 km apogee and 10∘ inclination to provide full sampling of the Van Allen radiation belts. The twin RBSP observatories (recently renamed the Van Allen Probes) will follow slightly different orbits and will lap each other four times per year, offering simultaneous measurements over a range of observatory separation distances. A description of the observatory environment is provided along with protection for sensitive electronics to support operations in the harsh radiation belt environment. Spacecraft and subsystem key characteristics and instrument accommodations are included that allow the RBSP science objectives to be met.

  3. Preservation of meandering river channels in uniformly aggrading channel belts

    NARCIS (Netherlands)

    van de Lageweg, W.I.; Schuurman, F.; Cohen, K.M.; van Dijk, W. M.; Shimizu, Y.; Kleinhans, M.G.

    2016-01-01

    Channel belt deposits from meandering river systems commonly display an internal architecture of stacked depositional features with scoured basal contacts due to channel and bedform migration across a range of scales. Recognition and correct interpretation of these bounding surfaces is essential to

  4. Resolving the Planetesimal Belt of HR 8799 with ALMA

    CERN Document Server

    Booth, Mark; Casassus, Simon; Hales, Antonio S; Dent, William R F; Faramaz, Virginie; Matrà, Luca; Barkats, Denis; Brahm, Rafael; Cuadra, Jorge

    2016-01-01

    The star HR 8799 hosts one of the largest known debris discs and at least four giant planets. Previous observations have found evidence for a warm belt within the orbits of the planets, a cold planetesimal belt beyond their orbits and a halo of small grains. With the infrared data, it is hard to distinguish the planetesimal belt emission from that of the grains in the halo. With this in mind, the system has been observed with ALMA in band 6 (1.34 mm) using a compact array format. These observations allow the inner edge of the planetesimal belt to be resolved for the first time. A radial distribution of dust grains is fitted to the data using an MCMC method. The disc is best fit by a broad ring between $145^{+12}_{-12}$ AU and $429^{+37}_{-32}$ AU at an inclination of $40^{+5}_{-6}${\\deg} and a position angle of $51^{+8}_{-8}${\\deg}. A disc edge at ~145 AU is too far out to be explained simply by interactions with planet b, requiring either a more complicated dynamical history or an extra planet beyond the orb...

  5. Monitoring, Analyzing and Assessing Radiation Belt Loss and Energization

    Science.gov (United States)

    Daglis, I. A.; Bourdarie, S.; Khotyaintsev, Y.; Santolik, O.; Horne, R.; Mann, I.; Turner, D.

    2012-04-01

    We present the concept, objectives and expected impact of the MAARBLE (Monitoring, Analyzing and Assessing Radiation Belt Loss and Energization) project, which is being implemented by a consortium of seven institutions (five European, one Canadian and one US) with support from the European Community's Seventh Framework Programme. The MAARBLE project employs multi-spacecraft monitoring of the geospace environment, complemented by ground-based monitoring, in order to analyze and assess the physical mechanisms leading to radiation belt particle energization and loss. Particular attention is paid to the role of ULF/VLF waves. A database containing properties of the waves is being created and will be made available to the scientific community. Based on the wave database, a statistical model of the wave activity dependent on the level of geomagnetic activity, solar wind forcing, and magnetospheric region will be developed. Multi-spacecraft particle measurements will be incorporated into data assimilation tools, leading to new understanding of the causal relationships between ULF/VLF waves and radiation belt dynamics. Data assimilation techniques have been proven as a valuable tool in the field of radiation belts, able to guide 'the best' estimate of the state of a complex system. (The members of the MAARBLE team are: I. A. Daglis, S. Bourdarie, Y. Khotyaintsev, O. Santolik, R. Horne, I. Mann, D. Turner, A. Anastasiadis, V. Angelopoulos, G. Balasis, E. Chatzichristou, C. Cully, M. Georgiou, S. Glauert, B. Grison, I. Kolmasova, D. Lazaro, E. Macusova, V. Maget, C. Papadimitriou, G. Ropokis, I. Sandberg, M. Usanova.)

  6. Smoking, Sociodemographic Determinants, and Stress in the Alabama Black Belt

    Science.gov (United States)

    Shuaib, Faisal; Foushee, H. R.; Ehiri, John; Bagchi, Suparna; Baumann, Angela; Kohler, Connie

    2011-01-01

    Purpose: In the Alabama Black Belt, poverty is high, and the educational level is low. Studies have found increased tobacco use among individuals exposed to high levels of stress. Few studies have been conducted in this region to measure smoking status, its sociodemographic determinants, and how smoking status relates to stressful environmental…

  7. Paired Magmatic-Metallogenic Belts in Myanmar - an Andean Analogue?

    Science.gov (United States)

    Gardiner, Nicholas; Robb, Laurence; Searle, Michael; Morley, Christopher

    2015-04-01

    Myanmar (Burma) is richly endowed in precious and base metals, having one of the most diverse collections of natural resources in SE Asia. Its geological history is dominated by the staged closing of Tethys and the suturing of Gondwana-derived continental fragments onto the South China craton during the Mesozoic-Cenozoic. The country is located at a crucial geologic juncture where the main convergent Tethyan collision zone swings south around the Namche Barwa Eastern Himalayan syntaxis. However, despite recent work, the geological and geodynamic history of Myanmar remains enigmatic. Plate margin processes, magmatism, metasomatism and the genesis of mineral deposits are intricately linked, and there has long been recognized a relationship between the distribution of certain mineral deposit types, and the tectonic settings which favour their genesis. A better knowledge of the regional tectonic evolution of a potential exploration jurisdiction is therefore crucial to understanding its minerals prospectivity. This strong association between tectonics and mineralization can equally be applied in reverse. By mapping out the spatial, and temporal, distribution of presumed co-genetic mineral deposits, coupled with an understanding of their collective metallogenetic origin, a better appreciation of the tectonic evolution of a terrane may be elucidated. Identification and categorization of metallotects within a geodynamically-evolving terrane thus provides a complimentary tool to other methodologies (e.g. geochemical, geochronological, structural, geophysical, stratigraphical), for determining the tectonic history and inferred geodynamic setting of that terrane through time. Myanmar is one such study area where this approach can be undertaken. Here are found two near-parallel magmatic belts, which together contain a significant proportion of that country's mineral wealth of tin, tungsten, copper, gold and silver. Although only a few 100 km's apart, these belts exhibit a

  8. Belt(s) of debris resolved around the Sco-Cen star HIP 67497

    CERN Document Server

    Bonnefoy, M; Ménard, F; Vigan, A; Lagrange, A -M; Delorme, P; Boccaletti, A; Lazzoni, C; Galicher, R; Desidera, S; Chauvin, G; Augereau, J C; Mouillet, D; Pinte, C; van der Plas, G; Gratton, R; Beust, H; Beuzit, J L

    2016-01-01

    In 2015, we initiated a survey of Scorpius-Centaurus A-F stars that are predicted to host warm-inner and cold-outer belts of debris similar to the case of the system HR~8799. The survey aims to resolve the disks and detect planets responsible for the disk morphology. In this paper, we study the F-type star HIP~67497 and present a first-order modelisation of the disk in order to derive its main properties. We used the near-infrared integral field spectrograph (IFS) and dual-band imager IRDIS of VLT/SPHERE to obtain angular-differential imaging observations of the circumstellar environnement of HIP~67497. We removed the stellar halo with PCA and TLOCI algorithms. We modeled the disk emission with the GRaTeR code. We resolve a ring-like structure that extends up to $\\sim$450 mas ($\\sim$50 au) from the star in the IRDIS and IFS data. It is best reproduced by models of a non-eccentric ring with an inclination of $80\\pm1^{\\circ}$, a position angle of $-93\\pm1^{\\circ}$, and a semi-major axis of $59\\pm3$ au. We also ...

  9. Compositional variations in the Mesoarchean chromites of the Nuggihalli schist belt, Western Dharwar Craton (India)

    DEFF Research Database (Denmark)

    Mukherjee, Ria; Mondal, Sisir Kanti; Rosing, Minik Thorleif

    2010-01-01

    -98)) and pyroxene grains (Mg-numbers = 97-99). Compositional variability on the scale of a single chromite grain occurs in the form of zoning, and it is common in the accessory chromite grains in serpentinite and in the altered grains in chromitite. In the zoned grains, the composition of the core is modified...... has been used to compute the nature of the parental melt. The parental melt calculations indicate derivation from a high-Mg komatiitic basalt that is similar to the composition of the komatiitic rocks reported from the greenstone sequences of the Western Dharwar Craton. Tectonic discrimination...

  10. Evaluation of legislation on seat belt use on rear seats : social persuasion as a new measure to promote seat belt use.

    OpenAIRE

    1996-01-01

    In the Netherlands, the use of seat belts for front seat passengers was made compulsory in 1975, and on April 1st 1992 the use of rear seat belts, if fitted, became a legal requirement. Since 1968, an annual survey of the presence and use of seat belts on front seats - extended in 1989 to include rear seats - has been conducted in the Netherlands. An evaluation of compliance with the law stipulating the use of rear seat belts was conducted by comparing the observation and surveys carried out ...

  11. Comparison of two pelvic positioning belt configurations in a pediatric wheelchair.

    Science.gov (United States)

    Cimolin, Veronica; Avellis, Martino; Piccinini, Luigi; Corbetta, Claudio; Cazzaniga, Andrea; Turconi, Anna Carla; Galli, Manuela

    2013-01-01

    Maintenance of stability for children in a wheelchair, particularly for those with spasticity, can be achieved through external stabilization components, such as pelvic positioning belts. Different kinds of pelvic belts exist on the market and one of the main characteristics is the different number of attachment points between the seat and the belt. As literature on this topic is limited to qualitative assessments, this study compared quantitatively 4-point versus 2-point pelvic positioning belts for the trunk fixation in 20 young patients with spasticity. Our data showed that 70% of the children required the use of pelvic belts on wheelchairs for stability and a better stability was observed with the 4-point belts than compared to the 2-point. Data generally showed in fact a higher percent of variation in terms of trunk flexion angleand knee joint angle with the 2-point belt than the 4-point belt, indicating increased submarining with the 2-point belt during sitting maintenance if compared to the 4-point belt (p < 0.05). According to our results, the 4-point belts seem to be the most effective configuration for patient stabilization, suggesting that its use prevents the thigh from submarining.

  12. Intrusive rocks and plutonic belts of southeastern Alaska, U.S.A.

    Science.gov (United States)

    Brew, David A.; Morrell, Robert P.; Roddick, J.A.

    1983-01-01

    About 30 percent of the 175,000-km2 area of southeastern Alaska is underlain by intrusive igneous rocks. Compilation of available information on the distribution, composition, and ages of these rocks indicates the presence of six major and six minor plutonic belts. From west to east, the major belts are: the Fairweather-Baranof belt of early to mid-Tertiary granodiorite; the Muir-Chichagof belt of mid-Cretaceous tonalite and granodiorite; the Admiralty-Revillagigedo belt of porphyritic granodiorite, quartz diorite, and diorite of probable Cretaceous age; the Klukwan-Duke belt of concentrically zoned or Alaskan-type ultramafic-mafic plutons of mid-Cretaceous age within the Admiralty-Revillagigedo belt; the Coast Plutonic Complex sill belt of tonalite of unknown, but perhaps mid-Cretaceous, age; and the Coast Plutonic Complex belt I of early to mid-Tertiary granodiorite and quartz monzonite. The minor belts are distributed as follows: the Glacier Bay belt of Cretaceous and(or) Tertiary granodiorite, tonalite, and quartz diorite lies within the Fair-weather-Baranof belt; layered gabbro complexes of inferred mid-Tertiary age lie within and are probably related to the Fairweather-Baranof belt; the Chilkat-Chichagof belt of Jurassic granodiorite and tonalite lies within the Muir-Chichagof belt; the Sitkoh Bay alkaline, the Kendrick Bay pyroxenite to quartz monzonite, and the Annette and Cape Fox trondhjemite plutons, all interpreted to be of Ordovician(?) age, together form the crude southern southeastern Alaska belt within the Muir-Chichagof belt; the Kuiu-Etolin mid-Tertiary belt of volcanic and plutonic rocks extends from the Muir-Chichagof belt eastward into the Admiralty-Revillagigedo belt; and the Behm Canal belt of mid- to late Tertiary granite lies within and next to Coast Plutonic Complex belt II. In addition, scattered mafic-ultramafic bodies occur within the Fairweather-Baranof, Muir-Chichagof, and Coast Plutonic Complex belts I and II. Palinspastic

  13. DEVELOPMENT OF THE TEST METHODS OF THE CONVEYOR BELTS USED IN ENVIRONMENTS ENDANGERED BY EXPLOSION HAZARDS

    Directory of Open Access Journals (Sweden)

    Florin Adrian PĂUN

    2012-05-01

    Full Text Available Conveyor belts are used for a long period of time in the industry branches where potentially explosive atmospheres could occur. Dangerous phenomena which can be in direct connection with the use of conveyor belts are the ones regarding: - sparks influence over the coating layer and/or resistance internal structure of the stopped conveyor belt; - propagation of a flame along the length of a conveyor belt that was exposed to a energy source relative high like a fire or due to blockage of a conveyor belt as a result of the driving mechanism still operating, that generate a local heating of the conveyor belt in contact with the driving drum, rollers or any other heating source generated by friction. Determining the safety parameters characteristic of the conveyor belts by employing test methods allows assessment of the safety level as well as certification of their explosion protection quality when used in environments with explosion danger.

  14. Dynamics of the earth's radiation belts and inner magnetosphere (geophysical monograph series)

    CERN Document Server

    2013-01-01

    Dynamics of the Earth's Radiation Belts and Inner Magnetosphere draws together current knowledge of the radiation belts prior to the launch of Radiation Belt Storm Probes (RPSP) and other imminent space missions, making this volume timely and unique. The volume will serve as a useful benchmark at this exciting and pivotal period in radiation belt research in advance of the new discoveries that the RPSP mission will surely bring. Highlights include the following: a review of the current state of the art of radiation belt science; a complete and up-to-date account of the wave-particle interactions that control the dynamical acceleration and loss processes of particles in the Earth's radiation belts and inner magnetosphere; a discussion emphasizing the importance of the cross-energy coupling of the particle populations of the radiation belts, ring current, and plasmasphere in controlling the dynamics of the inner magnetosphe...

  15. Factors associated with seat belt use: an evaluation from the Ontario Health Survey.

    Science.gov (United States)

    Sahai, V S; Pitblado, J R; Bota, G W; Rowe, B H

    1998-01-01

    This study examines the factors associated with seat belt use for drivers and passengers in Ontario. Using the 1990 Ontario Health Survey, a population-based survey of non-institutionalized Ontario residents, factors associated with seat belt use among drivers and passengers were identified and are reported as unadjusted and adjusted odds ratios (OR; 95% CI). Seat belt non-use in Ontario drivers was most strongly associated with younger age (p Seat belt non-use in passengers was associated with younger age (p seat belt use has been shown to reduce injuries in the event of a crash. Any strategy to increase seat belt use in Ontario should be targeted to involve both drivers and passengers. Attention should be paid to increasing seat belt usage by younger adults, males, and especially those living in northern and rural regions.

  16. Self-reported safety belt use among emergency department patients in Boston, Massachusetts

    Directory of Open Access Journals (Sweden)

    Mitchell Patricia

    2006-04-01

    Full Text Available Abstract Background Safety belt use is 80% nationally, yet only 63% in Massachusetts. Safety belt use among potentially at-risk groups in Boston is unknown. We sought to assess the prevalence and correlates of belt non-use among emergency department (ED patients in Boston. Methods A cross-sectional survey with systematic sampling was conducted on non-urgent ED patients age ≥18. A closed-ended survey was administered by interview. Safety belt use was defined via two methods: a single-item and a multiple-item measure of safety belt use. Each was scored using a 5-point frequency scale. Responses were used to categorize safety belt use as 'always' or less than 'always'. Outcome for multivariate logistic regression analysis was safety belt use less than 'always'. Results Of 478 patients approached, 381 (80% participated. Participants were 48% female, 48% African-American, 40% White, median age 39. Among participants, 250 (66% had been in a car crash; 234 (61% had a valid driver's license, and 42 (11% had been ticketed for belt non-use. Using two different survey measures, a single-item and a multiple-item measure, safety belt use 'always' was 51% and 36% respectively. According to separate regression models, factors associated with belt non-use included male gender, alcohol consumption >5 drinks in one episode, riding with others that drink and drive, ever receiving a citation for belt non-use, believing that safety belt use is 'uncomfortable', and that 'I just forget', while 'It's my usual habit' was protective. Conclusion ED patients at an urban hospital in Boston have considerably lower self-reported safety belt use than state or national estimates. An ED-based intervention to increase safety belt use among this hard-to-reach population warrants consideration.

  17. 23 CFR 1240.11 - Determination of State seat belt use rate for calendar years 1996 and 1997.

    Science.gov (United States)

    2010-04-01

    ... 23 Highways 1 2010-04-01 2010-04-01 false Determination of State seat belt use rate for calendar... SEAT BELTS-ALLOCATIONS BASED ON SEAT BELT USE RATES Determination of Allocations § 1240.11 Determination of State seat belt use rate for calendar years 1996 and 1997. (a) Review of...

  18. Asteroid fission, binaries and the small main belt population

    Science.gov (United States)

    Rossi, A.; Jacobson, S.; Marzari, F.; Scheeres, D.

    2011-10-01

    Using a Monte Carlo method we model the spin evolution of small Main Belt asteroids under the joint effects of YORP and collisions. Our simulations allow us to estimate the fraction of asteroids undergoing rotational fission in different size ranges. When an asteroid reaches its disruption spin limit we determine the outcome of its subsequent evolution based on accumulated statistics on their evolution based on numerical integrations (i.e., binary or ternary formation, binary disruption, etc..). Our aim is to predict the percentage of binary asteroids and their properties in the Belt, the number of objects like P/2010 A2 per year and the effects of YORP-induced fission on the overall asteroid size distribution at the small size end.

  19. On the propagation of uncertainties in radiation belt simulations

    Science.gov (United States)

    Camporeale, Enrico; Shprits, Yuri; Chandorkar, Mandar; Drozdov, Alexander; Wing, Simon

    2016-11-01

    We present the first study of the uncertainties associated with radiation belt simulations, performed in the standard quasi-linear diffusion framework. In particular, we estimate how uncertainties of some input parameters propagate through the nonlinear simulation, producing a distribution of outputs that can be quite broad. Here we restrict our focus on two-dimensional simulations (in energy and pitch angle space) of parallel-propagating chorus waves only, and we study as stochastic input parameters the geomagnetic index Kp (that characterizes the time dependency of an idealized storm), the latitudinal extent of waves, and the average electron density. We employ a collocation method, thus performing an ensemble of simulations. The results of this work point to the necessity of shifting to a probabilistic interpretation of radiation belt simulation results and suggest that an accurate specification of a time-dependent density model is crucial for modeling the radiation environment.

  20. The asteroid belt outer region under jumping-Jupiter migration

    Science.gov (United States)

    Gaspar, H. S.; Winter, O. C.; Vieira Neto, E.

    2017-09-01

    The radial configuration of the outer region of the main asteroid belt is quite peculiar, and has much to say about the past evolution of Jupiter. In this work, we investigate the dynamical effects of a jumping-Jupiter-like migration over a more extended primordial asteroid belt. Jupiter's migrations are simulated using a fast jumping-Jupiter synthesizer. Among the results, we highlight non-negligible fractions of primordial objects trapped in 3:2 and 4:3 mean motion resonances (MMRs) with Jupiter. They survived the whole truculent phase of migration and originated populations that are like Hildas and Thules. Fractions ranging from 3 to 6 per cent of the initial distribution remained trapped in 3:2 MMR, and at least 0.05 per cent in 4:3. These results show that the resonance trapping of primordial objects may have originated these resonant populations. This theory is consistent even for Jupiter's truculent evolution.

  1. A deep space inventory tour of the main asteroid belt

    DEFF Research Database (Denmark)

    Gibbings, Alison; Bowles, Neil; Snodgrass, Colin

    2016-01-01

    A consortium of international scientists and industry partners are proposing the Main Belt Inventory Mission as a candidate in the next forthcoming ESA medium class mission call. The inventory mission will characterise a broad range of statistically significant asteroid samples throughout the Main...... Asteroid Belt (MAB). A 0.5 m aperture space-based telescope will conduct a detailed spectroscopic survey, observing thousands of objects from a range of 0.1-0.5 AU, and perform basic flybys of pre-selected targets. Each flyby will target an asteroid of a different size, taxonomic (sub)classes and orbital...... families, where spatially resolved spectral mapping and spectroscopy will be performed. Smaller and fainter passing targets will also be discovered, through opportunistic science, with dedicated star tracker-like cameras. Examining the compositional diversity across the asteroid population will provide...

  2. Cofilin activation during podosome belt formation in osteoclasts.

    Directory of Open Access Journals (Sweden)

    Anne Blangy

    Full Text Available Podosomes are dynamic actin-based structures found constitutively in cells of monocytic origin such as macrophages, dendritic cells and osteoclasts. They have been involved in osteoclast cell adhesion, motility and matrix degradation, and all these functions rely on the ability of podosomes to form supra-molecular structures called podosome belts or sealing zones on mineralized substrates. Podosomes contain two distinct domains, an actin-rich core enriched in actin polymerization regulators, surrounded by a ring of signaling and plaque molecules. The organization of podosome arrays into belts is linked to actin dynamics. Cofilin is an actin-severing protein that is known to regulate cytoskeleton architecture and cell migration. Cofilin is present in lamellipodia and invadopodia where it regulates actin polymerization. In this report, we show that cofilin is a novel component of the podosome belt, the mature osteoclast adhesion structure. Time-course analysis demonstrated that cofilin is activated during primary osteoclast differentiation, at the time of podosome belt assembly. Immunofluorescence studies reveal a localization of active cofilin in the podosome core structure, whereas phosphorylated, inactive cofilin is concentrated in the podosome cloud. Pharmacological studies unraveled the role of a specific cofilin phosphatase to achieve cofilin activation during osteoclast differentiation. We ruled out the implication of PP1/PP2A and PTEN in this process, and rather provided evidence for the involvement of SSH1. In summary, our data involve cofilin as a regulator of podosome organization that is activated during osteoclast differentiation by a RANKL-mediated signaling pathway targeting the SSH1 phosphatase.

  3. Discovery of the candidate Kuiper belt object 1992 QB1

    Science.gov (United States)

    Jewitt, D.; Luu, J.

    1993-04-01

    The discovery of a new faint object in the outer solar system, 1992 QB1, moving beyond the orbit of Neptune is reported. It is suggested that the 1992 QB1 may represent the first detection of a member of the Kuiper belt (Edgworth, 1949; Kuiper, 1951), the hypothesized population of objects beyond Neptune and a possible source of the short-period comets, as suggested by Whipple (1964), Fernandez (1980), and Duncan et al. (1988).

  4. Anomalous heat flow belt along the continental margin of Brazil

    Science.gov (United States)

    Hamza, Valiya M.; Vieira, Fabio P.; Silva, Raquel T. A.

    2017-06-01

    A comprehensive analysis of thermal gradient and heat flow data was carried out for sedimentary basins situated in the continental margin of Brazil (CMB). The results point to the existence of a narrow belt within CMB, where temperature gradients are higher than 30 °C/km and the heat flow is in excess of 70 mW/m2. This anomalous geothermal belt is confined between zones of relatively low to normal heat flow in the adjacent continental and oceanic regions. The width of the belt is somewhat variable, but most of it falls within the range of 100-300 km. The spatial extent is relatively large in the southern (in the basins of Pelotas, Santos and Campos) and northern (in the basins of Potiguar and Ceará) parts, when compared with those in the central parts (in the basins of South Bahia, Sergipe and Alagoas). The characteristics of heat flow anomalies appear to be compatible with those produced by thermal sources at depths in the lower crust. Hence, magma emplacement at the transition zone between lower crust and upper mantle is considered the likely mechanism producing such anomalies. Seismicity within the belt is relatively weak, with focal depths less than 10 km for most of the events. Such observations imply that "tectonic bonding" between continental and oceanic segments, at the transition zone of CMB, is relatively weak. Hence, it is proposed that passive margins like CMB be considered as constituting a type of plate boundary that is aseismic at sub-crustal levels, but allows for escape of significant amounts of earth's internal heat at shallow depths.

  5. Radiation Belt Electron Dynamics Driven by Large-Amplitude Whistlers

    Science.gov (United States)

    Khazanov, G. V.; Tel'nikhin, A. A.; Kronberg, T. K.

    2013-01-01

    Acceleration of radiation belt electrons driven by oblique large-amplitude whistler waves is studied. We show analytically and numerically that this is a stochastic process; the intensity of which depends on the wave power modified by Bessel functions. The type of this dependence is determined by the character of the nonlinear interaction due to coupling between action and phase. The results show that physically significant quantities have a relatively weak dependence on the wave power.

  6. Nonlinear Whistler Wave Physics in the Radiation Belts

    Science.gov (United States)

    Crabtree, Chris

    2016-10-01

    Wave particle interactions between electrons and whistler waves are a dominant mechanism for controlling the dynamics of energetic electrons in the radiation belts. They are responsible for loss, via pitch-angle scattering of electrons into the loss cone, and energization to millions of electron volts. It has previously been theorized that large amplitude waves on the whistler branch may scatter their wave-vector nonlinearly via nonlinear Landau damping leading to important consequences for the global distribution of whistler wave energy density and hence the energetic electrons. It can dramatically reduce the lifetime of energetic electrons in the radiation belts by increasing the pitch angle scattering rate. The fundamental building block of this theory has now been confirmed through laboratory experiments. Here we report on in situ observations of wave electro-magnetic fields from the EMFISIS instrument on board NASA's Van Allen Probes that show the signatures of nonlinear scattering of whistler waves in the inner radiation belts. In the outer radiation belts, whistler mode chorus is believed to be responsible for the energization of electrons from 10s of Kev to MeV energies. Chorus is characterized by bursty large amplitude whistler mode waves with frequencies that change as a function of time on timescales corresponding to their growth. Theories explaining the chirping have been developed for decades based on electron trapping dynamics in a coherent wave. New high time resolution wave data from the Van Allen probes and advanced spectral techniques are revealing that the wave dynamics is highly structured, with sub-elements consisting of multiple chirping waves with discrete frequency hops between sub-elements. Laboratory experiments with energetic electron beams are currently reproducing the complex frequency vs time dynamics of whistler waves and in addition revealing signatures of wave-wave and beat-wave nonlinear wave-particle interactions. These new data

  7. The absolute magnitude distribution of cold classical Kuiper belt objects

    Science.gov (United States)

    Petit, Jean-Marc; Bannister, Michele T.; Alexandersen, Mike; Chen, Ying-Tung; Gladman, Brett; Gwyn, Stephen; Kavelaars, JJ; Volk, Kathryn

    2016-10-01

    We report measurements of the low inclination component of the main Kuiper Belt showing a size freqency distribution very steep for sizes larger than H_r ~ 6.5-7.0 and then a flattening to shallower slope that is still steeper than the collisional equilibrium slope.The Outer Solar System Origins Survey (OSSOS) is ongoing and is expected to detect over 500 TNOs in a precisely calibrated and characterized survey. Combining our current sample with CFEPS and the Alexandersen et al. (2015) survey, we analyse a sample of ~180 low inclination main classical (cold) TNOs, with absolute magnitude H_r (SDSS r' like flter) in the range 5 to 8.8. We confirm that the H_r distribution can be approximated by an exponential with a very steep slope (>1) at the bright end of the distribution, as has been recognized long ago. A transition to a shallower slope occurs around H_r ~ 6.5 - 7.0, an H_r mag identified by Fraster et al (2014). Faintward of this transition, we find a second exponential to be a good approximation at least until H_r ~ 8.5, but with a slope significantly steeper than the one proposed by Fraser et al. (2014) or even the collisional equilibrium value of 0.5.The transition in the cold TNO H_r distribution thus appears to occur at larger sizes than is observed in the high inclination main classical (hot) belt, an important indicator of a different cosmogony for these two sub-components of the main classical Kuiper belt. Given the largish slope faintward of the transition, the cold population with ~100 km diameter may dominate the mass of the Kuiper belt in the 40 AU < a < 47 au region.

  8. Development of a new Global RAdiation Belt model: GRAB

    Science.gov (United States)

    Sicard-Piet, Angelica; Lazaro, Didier; Maget, Vincent; Rolland, Guy; Ecoffet, Robert; Bourdarie, Sébastien; Boscher, Daniel; Standarovski, Denis

    2016-07-01

    The well known AP8 and AE8 NASA models are commonly used in the industry to specify the radiation belt environment. Unfortunately, there are some limitations in the use of these models, first due to the covered energy range, but also because in some regions of space, there are discrepancies between the predicted average values and the measurements. Therefore, our aim is to develop a radiation belt model, covering a large region of space and energy, from LEO altitudes to GEO and above, and from plasma to relativistic particles. The aim for the first version is to correct the AP8 and AE8 models where they are deficient or not defined. At geostationary, we developed ten years ago for electrons the IGE-2006 model which was proven to be more accurate than AE8, and used commonly in the industry, covering a broad energy range, from 1keV to 5MeV. From then, a proton model for geostationary orbit was also developed for material applications, followed by the OZONE model covering a narrower energy range but the whole outer electron belt, a SLOT model to asses average electron values for 2file system to switch between models, in order to obtain at each location in space and energy point the most reliable value. Of course, the way the model is developed is well suited to add new local developments or to include international partnership. This model will be called the GRAB model, as Global Radiation Belt model. We will present first beta version during this conference.

  9. Rotational Period of Three Main-belt Asteroids

    Science.gov (United States)

    Ferrro, Andrea

    2017-04-01

    CCD photometric observations of three main-belt asteroids were made to find the synodic period and amplitude of their lightcurves: 1264 Letaba, P = 33.27 ± 0.01 h, A = 0.15 mag; 2407 Haug, P = 6.162 ± 0.002 h, A = 0.32 mag; and 5464 Weller, P = 3.288 ± 0.002 h, A = 0.35 mag.

  10. Energetic radiation belt electron precipitation showing ULF modulation

    Science.gov (United States)

    Brito, T. V.; Hudson, M. K.; Kress, B. T.

    2012-12-01

    The energization and loss processes for energetic radiation belt electrons are not yet well understood. Ultra Low Frequency (ULF) waves have been correlated with both enhancement in outer zone radiation belt electron flux and modulation of precipitation loss to the atmosphere. This study considers the effects of ULF waves in the Pc-4 to Pc-5 range on electron loss to the atmosphere on a time scale of several minutes. Global simulations using magnetohydrodynamics (MHD) model fields as drivers provide a valuable tool for studying the dynamics of these ˜MeV energetic particles. ACE satellite measurements of the MHD solar wind parameters are used as the upstream boundary condition for the Lyon-Fedder-Mobarry (LFM) 3D MHD code calculation of fields, used to drive electrons in a 3D test particle simulation that keeps track of attributes like energy, pitch-angle and L-shell. The simulation results are compared with balloon observations obtained during the January 21, 2005 CME-shock event. Rapid loss of 20~keV to 1.5~MeV electrons was detected by balloon-borne measurements of Bremsstrahlung X-rays during the MINIS balloon campaign following the shock arrival at Earth. The global response of the radiation belts to this particular CME-shock driven storm was investigated focusing on precipitation mechanisms by which ULF waves, seen both in the simulations and observations influence the radiation belt population. A primary cause for the precipitation modulation seen in both the simulation and the MINIS campaign is suggested based on the lowering of mirror points due to compressional magnetic field oscillations.

  11. Future aerosol reductions and widening of the northern tropical belt

    Science.gov (United States)

    Allen, Robert J.; Ajoku, Osinachi

    2016-06-01

    Observations show that the tropical belt has widened over the past few decades, a phenomenon associated with poleward migration of subtropical dry zones and large-scale atmospheric circulation. Although part of this signal is related to natural climate variability, studies have identified an externally forced contribution primarily associated with greenhouse gases (GHGs) and stratospheric ozone loss. Here we show that the increase in aerosols over the twentieth century has led to contraction of the northern tropical belt, thereby offsetting part of the widening associated with the increase in GHGs. Over the 21st century, however, when aerosol emissions are projected to decrease, the effects of aerosols and GHGs reinforce one another, both contributing to widening of the northern tropical belt. Models that have larger aerosol forcing, by including aerosol indirect effects on cloud albedo and lifetime, yield significantly larger Northern Hemisphere (NH) tropical widening than models with direct aerosol effects only. More targeted simulations show that future reductions in aerosols can drive NH tropical widening as large as greenhouse gases, and idealized simulations show the importance of NH midlatitude aerosol forcing. Mechanistically, the 21st century reduction in aerosols peaks near 40°N, which results in a corresponding maximum increase in surface solar radiation, NH midlatitude tropospheric warming amplification, and a poleward shift in the latitude of maximum baroclinicity, implying a corresponding shift in atmospheric circulation. If models with aerosol indirect effects better represent the real world, then future aerosol changes are likely to be an important -- if not dominant -- driver of NH tropical belt widening.

  12. Solar System evolution from compositional mapping of the asteroid belt.

    Science.gov (United States)

    DeMeo, F E; Carry, B

    2014-01-30

    Advances in the discovery and characterization of asteroids over the past decade have revealed an unanticipated underlying structure that points to a dramatic early history of the inner Solar System. The asteroids in the main asteroid belt have been discovered to be more compositionally diverse with size and distance from the Sun than had previously been known. This implies substantial mixing through processes such as planetary migration and the subsequent dynamical processes.

  13. Rotation Period Determination of Four Main-belt Asteroids

    Science.gov (United States)

    Ferrero, Andrea

    2016-10-01

    Observations of four main-belt asteroids (MBA) revealed the following rotation periods and lightcurve amplitudes: 3861 Lorenz, P = 11.91 ± 0.01 h, A = 0.28 mag; 6173 Jimwestphal P = 2.908 ± 0.001 h, A = 0.41 mag; 10259 Osipovyurij, P = 6.356 ± 0.001 h, A = 0.30 mag; 29470 Higgs, P = 36.31 ± 0.01 h, A = 0.48 mag.

  14. Coralling a distant planet with extreme resonant Kuiper belt objects

    CERN Document Server

    Malhotra, Renu; Wang, Xianyu

    2016-01-01

    The four longest period Kuiper belt objects have orbital periods close to small integer ratios with each other. A hypothetical planet with orbital period $\\sim$17,117 years, semimajor axis $\\sim$665 AU, would have N/1 and N/2 period ratios with these four objects. The orbital geometries and dynamics of resonant orbits constrain the orbital plane, the orbital eccentricity and the mass of such a planet, as well as its current location in its orbital path.

  15. Structural setting of the Apennine-Maghrebian thrust belt

    Institute of Scientific and Technical Information of China (English)

    PieroElter; MarioGrasso; MaurizioParotto; LivioVezzani

    2003-01-01

    The Apennine-Maghrebian fold-and-thrust belt devel-oped from the latest Cretaceous to Early Pleistocene at the subduction-collisional boundary between the Euro-pean and the westward-subducted Ionian and Adria plates. Large parts of the Mesozoic oceanic lithosphere were subducted during an Alpine phase from the Late Cretaceous to Middle Eocene. The chain developed through the deformation of major paleogeographic internal domains (tectono-sedimentary sequences of the Ligurian-Piedmont Ocean) and external domains (sedi-mentary sequences derived from the deformation of the continental Adria-African passive mareinL The continu-ity of the Apennine chain is abruptly interrupted in the Calabrian Arc by the extensive klippe of Kabylo-Calabrian crystalline exotic terranes, derived from deformation of the European passive margin.Major complexities (sharp deflections in the arcuate configuration of the thrust belt, out-of-sequence propagation of the thrusts) are referred to contrasting rheology and differential buoyancy of the subducted lithosphere (transitional from conti-nental to oceanic) and consequent differential roll-back of the Adria plate margin, and to competence contrasts in the Mesozoic stratigraphic sequences,where multiple décollement horizons at different stratigraphic levels may have favored significant differential shortening.From the Late Miocene, the geometry of the thrust belt was strongly modified by extensional fault-ing, volcanic activity, crustal thinning and formation of oceanic crust correlated with the development of the Tyrrhenian Basin.

  16. Collisional Grooming Models of the Kuiper Belt Dust Cloud

    CERN Document Server

    Kuchner, Marc J

    2010-01-01

    We modeled the 3-D structure of the Kuiper Belt dust cloud at four different dust production rates, incorporating both planet-dust interactions and grain-grain collisions using the collisional grooming algorithm. Simulated images of a model with a face-on optical depth of ~10^-4 primarily show an azimuthally-symmetric ring at 40-47 AU in submillimeter and infrared wavelengths; this ring is associated with the cold classical Kuiper Belt. For models with lower optical depths (10^-6 and 10^-7), synthetic infrared images show that the ring widens and a gap opens in the ring at the location of of Neptune; this feature is caused by trapping of dust grains in Neptune's mean motion resonances. At low optical depths, a secondary ring also appears associated with the hole cleared in the center of the disk by Saturn. Our simulations, which incorporate 25 different grain sizes, illustrate that grain-grain collisions are important in sculpting today's Kuiper Belt dust, and probably other aspects of the Solar System dust c...

  17. Investigating radiation belt losses though numerical modelling of precipitating fluxes

    Directory of Open Access Journals (Sweden)

    C. J. Rodger

    2004-11-01

    Full Text Available It has been suggested that whistler-induced electron precipitation (WEP may be the most significant inner radiation belt loss process for some electron energy ranges. One area of uncertainty lies in identifying a typical estimate of the precipitating fluxes from the examples given in the literature to date. Here we aim to solve this difficulty through modelling satellite and ground-based observations of onset and decay of the precipitation and its effects in the ionosphere by examining WEP-produced Trimpi perturbations in subionospheric VLF transmissions. In this study we find that typical Trimpi are well described by the effects of WEP spectra derived from the AE-5 inner radiation belt model for typical precipitating energy fluxes. This confirms the validity of the radiation belt lifetimes determined in previous studies using these flux parameters. We find that the large variation in observed Trimpi perturbation size occurring over time scales of minutes to hours is primarily due to differing precipitation flux levels rather than changing WEP spectra. Finally, we show that high-time resolution measurements during the onset of Trimpi perturbations should provide a useful signature for discriminating WEP Trimpi from non-WEP Trimpi, due to the pulsed nature of the WEP arrival.

  18. Inner radiation belt source of helium and heavy hydrogen isotopes

    Science.gov (United States)

    Leonov, A. A.; Galper, A. M.; Koldashov, S. V.; Mikhailov, V. V.; Casolino, M.; Picozza, P.; Sparvoli, R.

    Nuclear interactions between inner zone protons and atoms in the upper atmosphere provide the main source of energetic H and He isotopes nuclei in the radiation belt. This paper reports on the specified calculations of these isotope intensities using various inner zone proton intensity models (AP-8 and SAMPEX/PET PSB97), the atmosphere drift-averaged composition and density model MSIS-90, and cross-sections of the interaction processes from the GNASH nuclear model code. To calculate drift-averaged densities and energy losses of secondaries, the particles were tracked in the geomagnetic field (modelled through IGRF-95) by integrating numerically the equation of the motion. The calculations take into account the kinematics of nuclear interactions along the whole trajectory of trapped proton. The comparison with new data obtained from the experiments on board RESURS-04 and MITA satellites and with data from SAMPEX and CRRES satellites taken during different phases of solar activity shows that the upper atmosphere is a sufficient source for inner zone helium and heavy hydrogen isotopes. The calculation results are energy spectra and angular distributions of light nuclear isotopes in the inner radiation belt that may be used to develop helium inner radiation belt model and to evaluate their contribution to SEU (single event upset) rates.

  19. Modeling the Inner Magnetosphere: Radiation Belts, Ring Current, and Composition

    Science.gov (United States)

    Glocer, Alex

    2011-01-01

    The space environment is a complex system defined by regions of differing length scales, characteristic energies, and physical processes. It is often difficult, or impossible, to treat all aspects of the space environment relative to a particular problem with a single model. In our studies, we utilize several models working in tandem to examine this highly interconnected system. The methodology and results will be presented for three focused topics: 1) Rapid radiation belt electron enhancements, 2) Ring current study of Energetic Neutral Atoms (ENAs), Dst, and plasma composition, and 3) Examination of the outflow of ionospheric ions. In the first study, we use a coupled MHD magnetosphere - kinetic radiation belt model to explain recent Akebono/RDM observations of greater than 2.5 MeV radiation belt electron enhancements occurring on timescales of less than a few hours. In the second study, we present initial results of a ring current study using a newly coupled kinetic ring current model with an MHD magnetosphere model. Results of a dst study for four geomagnetic events are shown. Moreover, direct comparison with TWINS ENA images are used to infer the role that composition plays in the ring current. In the final study, we directly model the transport of plasma from the ionosphere to the magnetosphere. We especially focus on the role of photoelectrons and and wave-particle interactions. The modeling methodology for each of these studies will be detailed along with the results.

  20. Non-Vestoid candidates in the inner Main Belt

    Science.gov (United States)

    Moskovitz, Nicholas; Oszkiewicz, Dagmara; Skiff, Brian; Kankiewicz, Pawel; Licandro, Javier; Galiazzo, Mattia; Zeilinger, Werner

    2016-10-01

    Most Howardite-Eucrite-Diogenite (HED) meteorites (analogues to V-type asteroids) are thought to originate from asteroid (4) Vesta. However some HEDs show distinct oxygen isotope ratios and therefore are thought to originate from other asteroids. In this study we try to identify asteroids that may represent parent bodies of those mismatching HEDs. In particular the origin of the anomalous Bunburra Rockhole meteorite was traced back to the inner main asteroid belt, showing that there might be asteroids that are not genetically linked to the asteroid (4) Vesta (the main source of V-type asteroids and HED meteorites) in the inner main belt. In this work we identify V-type asteroids outside the dynamical Vesta family whose rotational properties (retrograde vs prograde rotation) suggest the direction of Yarkovsky drift that sets them apart from typical Vestoids and Vesta fugitives. Specificly Nesvorny et al. 2008 simulated escapes paths from the Vesta family and showed that typical Vesta fugitives in the inner main asteroid belt at semi-major axis a drift or showing Yarkovsky drift direction towards (4) Vesta are the best candidates for non-Vestoidal V-type asteroids and therefore parent bodies of anomalous HED. In this study we have performed accurate photometric observations and determined sense of rotation for several asteroids testing their links to Vesta and anomalous HED. We have found several potential non-Vestoid candidates. Those objects have to be studied in more detail to fully confirm their link to anomalous HEDs.

  1. Control strategy of disc braking systems for downward belt conveyors

    Institute of Scientific and Technical Information of China (English)

    Hou Youfu; Xie Fangwei; Huang Fei

    2011-01-01

    Reliability of braking systems is a key requirement to ensure the safety of in using downward belt conveyor brakes.By analyzing and comparing three commonly used braking velocity curves,we conclude that the Harrison curve is the best.Given the characteristics of a downward belt conveyor,we studied the control in a closed-loop velocity,a conventional PID method and an optimal PID control method.We used MATLAB/Simulink to simulate the three control methods.Our simulation results show that optimal PID control is especially suitable for disc braking systems.To verify the results from theoretical analysis and simulation,a multifunctional test-bed was developed to simulate the braking process of a disc brake system.Our experimental results demonstrate that the optimal PID control can make the output velocity to follow a preset velocity correctly with only small fluctuations,meeting the requirements of a flexible brake for a belt conveyor.

  2. Metallogenic belt and mineral deposit maps of northeast Asia

    Science.gov (United States)

    Obolenskiy, Alexander A.; Rodionov, Sergey M.; Dejidmaa, Gunchin; Gerel, Ochir; Hwang, Duk-Hwan; Miller, Robert J.; Nokleberg, Warren J.; Ogasawara, Masatsugu; Smelov, Alexander P.; Yan, Hongquan; Seminskiy, Zhan V.

    2013-01-01

    This report contains explanatory material and summary tables for lode mineral deposits and placer districts (Map A, sheet 1) and metallogenic belts of Northeast Asia (Maps B, C, and D on sheets 2, 3, and 4, respectively). The map region includes eastern Siberia, southeastern Russia, Mongolia, northeast China, and Japan. A large group of geologists—members of the joint international project, Major Mineral Deposits, Metallogenesis, and Tectonics of Northeast Asia—prepared the maps, tables, and introductory text. This is a cooperative project with the Russian Academy of Sciences, Mongolian Academy of Sciences, Mongolian National University, Ulaanbaatar, Mongolian Technical University, Mineral Resources Authority of Mongolia, Geological Research Institute, Jilin University, China Geological Survey, Korea Institute of Geoscience and Mineral Resources, Geological Survey of Japan, and U.S. Geological Survey. This report is one of a series of reports on the mineral resources, geodynamics, and metallogenesis of Northeast Asia. Companion studies include (1) a detailed geodynamics map of Northeast Asia (Parfenov and others, 2003); (2) a compilation of major mineral deposit models (Rodionov and Nokleberg, 2000; Rodionov and others, 2000); (3) a series of metallogenic belt maps (Obolenskiy and others, 2004); (4) location map of lode mineral deposits and placer districts of Northeast Asia (Ariunbileg and others, 2003b); (5) descriptions of metallogenic belts (Rodionov and others, 2004); (6) a database on significant metalliferous and selected nonmetalliferous lode deposits and selected placer districts (Ariunbileg and others, 2003a); and (7) a series of summary project publications (Ariunbileg and 74 others, 2003b).

  3. Detection of Small Kuiper Belt Objects by Stellar Occultations

    CERN Document Server

    Stevenson, R

    2007-01-01

    Knowledge of the Kuiper Belt is currently limited to those objects that can be detected directly. Objects with diameters less than $\\sim$10km reflect too little light to be detected. These smaller bodies could contain most of the mass in the Kuiper Belt while the abundance of these bodies may constrain the distribution of mass. The overall size distribution of bodies within the Kuiper Belt can also be inferred from the relative abundances of sub-km and larger bodies. Stellar occultations are already used to study dark objects in the Solar System, such as asteroids or planetary rings. Occultation by a KBO of a size comparable to, or larger than, that of the Fresnel Scale will result in Fresnel diffraction. Detection of diffraction effects requires fast multiple-star photometry, which will be conducted in July 2007 using the Orthogonal Parallel Transfer Imaging Camera (OPTIC) mounted on the University of Hawaii 2.2m telescope on Mauna Kea. This paper details how knowledge of the mass and structure of the outer ...

  4. Periodicity in tree rings from the corn belt.

    Science.gov (United States)

    Meko, D M; Stockton, C W; Blasing, T J

    1985-07-26

    Previous tree-ring studies indicated that the total area affected by drought in the western United States has rhythmically expanded and contracted over the past 300 years, with a period near the 18.6-year lunar nodal and 22-year double-sunspot cycles. Recently collected tree-ring data from the U.S. Corn Belt for the years 1680 to 1980 were examined for evidence of either of these cycles on a regional scale. Spectral analysis indicated no periodicity in the eastern part of the Corn Belt, but a significant 18.33-year period in the western part. The period length changed from 17.60 to 20.95 years between the first 150 years and the last 151. High-resolution frequency analysis showed that the structure of the 18.33-year spectral peak was complex, with contributions from several frequencies near both the lunar nodal and double-sunspot periods. A t-test of difference of means in reconstructed annual precipitation weakly corroborated a previous finding of an association between drought area and the phase of the double-sunspot cycle. Both the high-resolution frequency analysis and the t-test results indicate that the periodic component of drought near 20 years is too weak and irregular to be of use in drought forecasting for the Corn Belt.

  5. Tool Belts: Latitudinal-Belt Predictions for the Persistence of Landscapes

    Science.gov (United States)

    Willenbring, Jane; Brocard, Gilles

    2016-04-01

    The ability of rivers to cut through rock and re-establish equilibrium sets the pace of landscape response to uplift. Because of associations between tectonics, erosion, and weathering, high rates of rock uplift may initiate a cascade of processes that are linked to high rates of weathering and eventually sequestration of CO2 over geologic timescales. How long does it take to completely change the topographic form after uplift and where on Earth do relict landscapes persist despite uplift? Large expanses of subdued landscapes are common at high elevation in mountain ranges. Preservation of subdued fragments amongst steeply dissected regions can therefore be a simple matter of chance, reflecting the time it takes for dissection to remove any remaining parcel of the pre-existing topography after a tectonic perturbation. Some of these relicts may, however, possess characteristics - often a product of the climate - that make them intrinsically resistant to dissection. One common mode of conversion of a subdued landscape into a deeply dissected one is the propagation of upstream-migrating erosion waves that transmit the signal of uplift and base level lowering across entire landscapes. Following a shift in tectonic forcing, the Earth's surface progressively adjusts its topographic form over millions of years, seeking to re-establish equilibrium with the new forcing. Here, we show that a high degree of weathering leading to smaller average soil grains at the surface hinders the capacity of rivers to incise. We show that globally, rates of cosmogenic nuclide-derived denudation rates fall into latitudinal belts with (1) low rates of denudation in areas with high temperatures and high precipitation where rock fragments do not persist at the soil surface, (2) high rates of denudation at mid-latitudes where rock fragments exist and are carried efficiently by the river flow, and (3) low rates of denudation at high latitudes where large grains at the surface inhibit channelized

  6. Evaluation of a brief intervention for increasing seat belt use on a college campus.

    Science.gov (United States)

    Pastò, L; Baker, A G

    2001-07-01

    The authors evaluated a brief intervention for increasing seat belt use among the front seat occupants of cars at a junior college, in a jurisdiction with a mandatory belt use law. The intervention included public posting of performance feedback and distribution of an informational flyer to cars in target parking lot. Feedback was the display of the proportion of drivers observed wearing seat belts on the previous observation day. Seat belt use among drivers increased from 64% during the baseline phase to 71% during the intervention phase. Seat belt use among front passengers increased from 49% during the baseline phase to 67% during the intervention phase. In both cases, seat belt use at follow-up was comparable to seat belt use during the intervention phase, although a trend toward decreasing belt use was noted. Also found was higher seat belt use among females as compared with males irrespective of their front seat occupant status (driver or passenger). Effects of the intervention are discussed in the context of increasing seat belt use in a hardcore nonuser population of predominantly young adults.

  7. Evaluation of pediatric use patterns and performance of lap shoulder belt systems in the center rear.

    Science.gov (United States)

    Arbogast, Kristy B; Durbin, Dennis R; Kallan, Michael J; Winston, Flaura K

    2004-01-01

    Lap and shoulder belts have been required in rear outboard positions since 1989. A recent congressional mandate encouraged the requirement of a lap and shoulder belt in the center rear seat position. This study utilized Data from the Partners for Child Passenger Safety study, a large-scale child-focused crash surveillance system, to quantify changes in seating patterns for children in vehicles that already have this feature compared to those which do not and measured the safety benefit associated with the provision of a shoulder belt in the center rear seat position. The data demonstrate that the presence of a shoulder belt in the center rear seating position influences seating practices only when there is a single child occupant in the vehicle. Belted children in the center rear of vehicles equipped with a lap shoulder belt are at an 81% reduction in risk of injury than those belted in the center rear equipped with a lap only belt. The data suggest that by requiring lap shoulder belts in the center rear, benefits would be realized to belted children, specifically the 4-8 year old group.

  8. Preventive Effects of Seat Belt on Clinical Outcomes for Road Traffic Injuries.

    Science.gov (United States)

    Kwak, Bong Hun; Ro, Young Sun; Shin, Sang Do; Song, Kyoung Jun; Kim, Yu Jin; Jang, Dayea Beatrice

    2015-12-01

    Proper seat belt use saves lives; however, the use rate decreased in Korea. This study aimed to measure the magnitude of the preventive effect of seat belt on case-fatality across drivers and passengers. We used the Emergency Department based Injury In-depth Surveillance (EDIIS) database from 17 EDs between 2011 and 2012. All of adult injured patients from road traffic injuries (RTI) in-vehicle of less than 10-seat van were eligible, excluding cases with unknown seat belt use and outcomes. Primary and secondary endpoints were in-hospital mortality and intracranial injury. We calculated adjusted odds ratios (AORs) of seat belt use and driving status for study outcomes adjusting for potential confounders. Among 23,698 eligible patients, 15,304 (64.6%) wore seat belts. Driver, middle aged (30-44 yr), male, daytime injured patients were more likely to use seat belts (all P seat belt group had higher proportions of case-fatality and intracranial injury compared to seat belt group (both P seat belt group, AORs (95% CIs) of no seat belt group were 10.43 (7.75-14.04) for case-fatality and 2.68 (2.25-3.19) for intracranial injury respectively. In the interaction model, AORs (95% CIs) of no seat belt use for case-fatality were 11.71 (8.45-16.22) in drivers and 5.52 (2.83-14.76) in non-driving passengers, respectively. Wearing seat belt has significantly preventive effects on case-fatality and intracranial injury. Public health efforts to increase seat belt use are needed to reduce health burden from RTIs.

  9. Mesozoic and Cenozoic tectonic evolution of the Longmenshan fault belt

    Institute of Scientific and Technical Information of China (English)

    WANG; ErChie

    2009-01-01

    The giant earthquake(Ms=8.0) in Wenchuan on May 12,2008 was triggered by oblique convergence between the Tibetan Plateau and the South China along the Longmenshan fault belt.The Longmenshan fault belt marks an important component of the tectonic and geomorphological boundary between the eastern and western part of China and has a protracted tectonic history.It was first formed as an intracontinental transfer fault,patitioning the differential deformation between the Pacific and Tethys tectonic domains,initiated in late Paleozoic-early Mesozoic time,then served as the eastern boundary of the Tibetan Plateau to accommodate the growth of the plateau in Cenozoic.Its current geological and geomorphological frameworks are the result of superimposition of these two tectonic events.In Late Triassic,the Longmenshan underwent left-slip oblique NW-SE shortening due to the clockwise rotation of the Yangtze Block,which led to the flexural subsidence of the Sichuan foreland basin,but after that,the subsidence of the Sichuan Basin seems no longer controlled by the tectonic activity of the Longmenshan fault belt.The Meosozoic tectonic evolution of the Songpan-Ganzi fold belt differs significantly compared with that of the Yangtze Platform,featured by intensive northeast and southwest shortening and resulted in the close of the Paleo-Tethys.Aerial photos taken immediately after main shock of the giant May 12,2008 earthquake have documented extensive rock fall and landslides that represent one of the most destructive aspects of the earthquake.Both rock avalanches and landslides delivered a huge volume of debris into the middle part of the Minjiang River,and formed many dammed lakes.Breaching of these natural dams can be catastrophic,as occurred in the Diexi area along the upstream of the Minjiang River in the year of 1933 that led to devastating floodings.The resultant flood following the breaching of these dams flowed through and out of the Longmenshan belt into the Chengdu Plain

  10. Mesozoic and Cenozoic tectonic evolution of the Longmenshan fault belt

    Institute of Scientific and Technical Information of China (English)

    WANG ErChie; MENG QingRen

    2009-01-01

    The giant earthquake (MS=8.0) in Wenchuan on May 12, 2008 was triggered by oblique convergence between the Tibetan Plateau and the South China along the Longmenshan fault belt. The Longmenshan fault belt marks an important component of the tectonic and geomorphological boundary between the eastern and western part of China and has a protracted tectonic history. It was first formed as an intracontinental transfer fault, patitioning the differential deformation between the Pacific and Tethys tectonic domains, initiated in late Paleozoic-early Mesozoic time, then served as the eastern boundary of the Tibetan Plateau to accommodate the growth of the plateau in Cenozoic. Its current geological and geomorphological frameworks are the result of superimposition of these two tectonic events. In Late Triassic, the Longmenshan underwent left-slip oblique NW-SE shortening due to the clockwise rotation of the Yangtze Block, which led to the flexural subsidence of the Sichuan foreland basin, but after that, the subsidence of the Sichuan Basin seems no longer controlled by the tectonic activity of the Longmenshan fault belt. The Meosozoic tectonic evolution of the Songpan-Ganzi fold belt differs significantly compared with that of the Yangtze Platform, featured by intensive northeast and southwest shortening and resulted in the close of the Paleo-Tethys. Aerial photos taken immediately after main shock of the giant May 12, 2008 earthquake have documented extensive rock fall and landslides that represent one of the most destructive aspects of the earthquake. Both rock avalanches and landslides delivered a huge volume of debris into the middle part of the Minjiang River, and formed many dammed lakes. Breaching of these natural dams can be catastrophic, as occurred in the Diexi area along the upstream of the Minjiang River in the year of 1933 that led to devastating floodings. The resultant flood following the breaching of these dams flowed through and out of the Longmenshan belt

  11. The constraints of strain partitioning and geochronology in Luonan-Luanchuan tectonic belts on Qinling orogenic belt

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The Luonan-Luanchuan tectonic belt lies between the North China Block and Qinling Mountains, in- cluding the Luonan-Luanchuan fault zone and the strong deformation zone to the north of the fault. The ductile shear zone, imbricate brittle fault and duplex structure in the fault zone now are the expression of the same tectonic event in different depth. Such lineation structure exists in the tectonic belts as mineral lineation, elongation lineation, crenulation lineation, sheath folds and so on, indicating NE-directed plate motion. Fold axes and thrusts in the strong deformation zone are inclined to the Luonan-Luanchuan fault zone at small angles. The structures with different natures show a regular pattern, produced during oblique convergence of plates. The convergence factors are as follows:The direction of plate convergence is 22°, 31° and the angle between the plate convergence direction and plate boundary is 73°, 82° respectively in the west and east segment. The Luonan-Luanchuan tectonic belt was deformed strongly in 372 Ma, resulted from Erlangping back-arc ocean basin subduction sin- istrally and obliquely to North China Block during the collision of North China Block and South China Block.

  12. The constraints of strain partitioning and geochronology in Luonan-Luanchuan tectonic belts on Qinling orogenic belt

    Institute of Scientific and Technical Information of China (English)

    SONG ChuanZhong; ZHANG GuoWei; WANG YongSheng; LI JiaHao; CHEN ZeChao; CAI ZhiChuan

    2009-01-01

    The Luonan-Luanchuan tectonic belt lies between the North China Block and Qinling Mountains,including the Luonan-Luanchuan fault zone and the strong deformation zone to the north of the fault.The ductile shear zone,imbricate brittle fault and duplex structure in the fault zone now are the expression of the same tectonic event in different depth.Such lineation structure exists in the tectonic belts as mineral lineation,elongation lineation,crenulation lineation,sheath folds and so on,indicating NE-directed plate motion.Fold axes and thrusts in the strong deformation zone are inclined to the Luonan-Luanchuan fault zone at small angles.The structures with different natures show a regular pattern,produced during oblique convergence of plates.The convergence factors are as follows:The direction of plate convergence is 22°,31° and the angle between the plate convergence direction and plate boundary is 73°,82° respectively in the west and east segment.The Luonan-Luanchuan tectonic belt was deformed strongly in 372 Ma,resulted from Erlangping back-arc ocean basin subduction sinistrally and obliquely to North China Block during the collision of North China Block and South China Block.

  13. The prevalence of seat belt use in Jamaica. An observational study.

    Science.gov (United States)

    Crandon, I W; Branday, J M; Simeon, D T; Rhoden, A; Thompson, H; Carpenter, R

    1996-03-01

    An observational cross-sectional survey showed that 21.1% of private motor vehicle drivers and 13.5% of front seat passengers voluntarily wore seat belts in Kingston, Jamaica, where there is no law requiring this. Rear passenger utilisation was not examined. Compared to males, females were significantly more likely to wear seat belts when driving but not as front seat passengers. Of all motor vehicles examined, 10.1% were not equipped with seat belts. The oldest group of vehicles were mostly not fitted with seat belts. Drivers of older vehicles were significantly less likely to use seat belts even when the vehicles were equipped with belts. Implementation of legislation can reduce mortality, morbidity and costs from road traffic accidents which are relatively frequent in Jamaica. Male drivers, drivers of older vehicles and all passengers may require specific targeting in an educational and enforcement campaign should legislation, which is highly desirable, be implemented.

  14. Possibilities for utilizing scrap rubber conveyor belts in manufacturing mine cars

    Energy Technology Data Exchange (ETDEWEB)

    Owinski, A.; Furmanik, K.

    1985-01-01

    Utilization of scrap conveyor belts removed due to wear in manufacturing mine cars used in underground coal mines is evaluated. Tests show that rubber packs (sandwiches) consisting of conveyor belt elements successfully replace springing in mine cars. The rubber packs are bent at an angle of 90 or 120 degrees to increase their damping properties. Evaluations show that service life of rubber springing is longer than 3 years. Replacing steel springs in car buffers with rubber belt packs is a further possibility. The rubber packs in car buffers absorb up to 35% of shock energy. Sections of scrap belts could also be used to reduce buildup of coal in mine cars. Belt sections are fastened to the bottom of mine cars. Belt deformation during car self-dumping (or unloading in a rotary tippler) reduces coal adhesion to the car body and prevents buildup. 4 references.

  15. Timing belts - development milestones and innovations; Meilensteine und Innovationen der Zahnriemenentwicklung

    Energy Technology Data Exchange (ETDEWEB)

    Schulte, H. [ContiTech Antriebssysteme GmbH, Hannover (Germany)

    2007-07-01

    Modern Timing Belts made of high temperature resistant elastomers for camshaft drives are designed for engine lifetime. Timing Belt drives gained in Europe 75% market share because of their advantages. The Belt drives generate up to 25% less friction than chain drives and create significantly lower noise levels. The new generation of Timing Belts are manufactured using: - special fibre glass types to transmit high forces with very high length stability - reinforced and Teflon treated fabrics to reduce friction and noise -high temperature resistant HNBR Elastomer to cover the temperature range (-40 C to +150 C) New belt drive developments are using Oval sprocket technology to eliminate unwanted vibrations and to reduce drive forces by 35%. Oil resistant Belts can substitute oil lubricated chains used for oil pump and camshaft drives to reduce the friction and noise level of the chain drives. (orig.)

  16. Seat belt syndrome in children: a case report and review of the literature.

    Science.gov (United States)

    Durbin, D R; Arbogast, K B; Moll, E K

    2001-12-01

    Characteristic patterns of injury to children in automobile crashes resulting from lap and lap-shoulder belts have been described for many years. These injuries are known as the "seat belt syndrome." We present a typical case of seat belt syndrome involving a 4-year-old boy and review the current literature on the topic, highlighting proposed mechanisms of intra-abdominal and spine injuries. In addition, recent research findings identifying a new pattern of injuries associated with inappropriate seat belt use in young children are reviewed. Emergency physicians must consider these seat belt-related injuries in the initial evaluation of any child involved in a motor vehicle crash who was restrained with the vehicle seat belt.

  17. Number of conveyor belts optimization regarding to its type and logistical parameters in mining industry

    Directory of Open Access Journals (Sweden)

    Dušan Malindžák

    2008-12-01

    Full Text Available Material transportation by belt conveyers is widely used in many industrial branches including mining plants. Belt conveyingdevelopment during the last year was oriented mainly on construction of belts. The consequence of this is the improvement of itsmanufacture qualities bringing down the costs for their exchange and maintenance.Despite the fact that there are some theoreticalcalculations based on a standards it is common in the industry that the belt is not properly selected or it is overdesigned or number of itstypes is too large what can lead to increased costs for its storage. The paper describes the optimization of number of belt types in miningcompany SIDERIT, s. r. o. Nižná Slaná by the method of modernization and unification of belts under practical skills and projectingbased on theoretical calculations.

  18. Standardization Overview of Belt Drive%带传动标准化综述

    Institute of Scientific and Technical Information of China (English)

    秦书安; 周玉杰; 周鹏

    2013-01-01

    结合国内外带传动标准化发展情况,阐述了我国带传动标准化的作用,提出了带传动标准化发展的建议.%Combining the development situation of standardixation of belt drive in home and abroad,the role of standardiztion of belt drive in China is expounded.The suggestion of standardization development in belt drive industry is proposed.

  19. The "One Belt and One Road" is an Important Mutually Beneficial and Win-win Strategy

    Institute of Scientific and Technical Information of China (English)

    Long; Kaifeng

    2015-01-01

    The"One Belt and One Road"strategic conception carries the dream of development and prosperity of countries concerned,and gives the ancient Silk Road a brand new content of the time.In September and October 2013,President Xi Jinping proposed building the"New Silk Road Economic Belt"(One Belt)and the"Twenty-first Century Maritime Silk Road"(One Road)strategic conception respectively,emphasizing a mutual-beneficial and win-win

  20. Investigation of used Conveyor Belts by the Differential Scanning Calorimetry Analysis

    Directory of Open Access Journals (Sweden)

    Lucia Knapcikova,

    2016-02-01

    Full Text Available In this paper is presented the use of differential scanning calorimetry analysis of the used conveyor belts. This method has been specifically tested on the individual components contained in the used conveyor belts esp. rubber pellets, cord and fabric. The result of the analysis is the determination of Tg temperature and melting temperatures (Tm by the components.Weanalyzed used conveyor belts and after this analysis it was determined components and their application to the industry

  1. Pattern of seat belt use by drivers in Trinidad and Tobago, West Indies

    Directory of Open Access Journals (Sweden)

    Odekunle Abayomi

    2011-06-01

    Full Text Available Abstract Background In Trinidad and Tobago, the law on the mandatory use of seat belts was passed in 1995, but this law is hardly enforced. The objective of this study was to determine the frequency and predictors of seat belt use by motor vehicle drivers in the country. Findings A cross-sectional study of 959 motor vehicle drivers using a self-administered questionnaire. Data analysis included Pearson Chi square test and multinomial logistic regression analysis in order to determine the possible predictors of seat belt use by the drivers in Trinidad and Tobago. A majority of the drivers sometimes (51.8% or always (31.6% use a seat belt. About 16.7%, 29% and 54.2% of the drivers perceived that the other drivers use their seat belts more frequently, with the same frequency and less frequently respectively compared to themselves. The main reason for not using seat belt by the drivers was given as frequent stops (40.7% and the main motivation to use seat belt by the drivers was given as stiffer penalties for non-compliance with the seat belt law (44.5%. The predictors of seat belt use were male driver, no formal or lower level of education, driving for less than 10 years, and the perception that the other drivers use seat belts with the same or higher frequency compared to the respondents. Conclusion Only a small proportion of the drivers in Trinidad and Tobago always use a seat belt when driving. There is the need to enforce the seat belt legislation in the country.

  2. Wave-induced loss of ultra-relativistic electrons in the Van Allen radiation belts

    OpenAIRE

    Yuri Shprits; A. Y. Drozdov; M. Spasojevic; A. C. Kellerman; M. E. Usanova; M. J. Engebretson; O. V. Agapitov; K. G. Orlova; I. S. Zhelavskaya; T. Raita; H. E. Spence; D. N. Baker; H. Zhu

    2016-01-01

    The dipole configuration of the Earth's magnetic field allows for the trapping of highly energetic particles, which form the radiation belts. Although significant advances have been made in understanding the acceleration mechanisms in the radiation belts, the loss processes remain poorly understood. Unique observations on 17 January 2013 provide detailed information throughout the belts on the energy spectrum and pitch angle (angle between the velocity of a particle and the magnetic field) di...

  3. Experimental Study of Kinetic Properties of Pyrolysis for Conveyor Belt in Coal Mine

    Institute of Scientific and Technical Information of China (English)

    SONG Zheng-chang

    2005-01-01

    The combustion of conveyor belt is a leading factor of mine fire. In this paper, the pyrolysis properties of ordinary conveyor belt and fire-resistant belt were studied experimentally with thermo-gravimetric analysis and derivative thermo-gravimetric analysis, and the curves of pyrolysis properties were achieved. On this basis, the activation energy and reaction order of pyrolysis were obtained in combination with theoretical analysis, aiming to provide data for further numerical simulation and simulating experiment of mine fire.

  4. Description of Timing Belt Coupling Using a Pendulum with Variable Coupling Point

    OpenAIRE

    Dudziak, Marian; Domek, Grzegorz

    2013-01-01

    In the description of the process of coupling of pulleys with the toothed belt often existing solutions are used. Depending on the application they are similar to flat belt, chain or hellical gears. Euler made a first approximation of the coupling by ratio of the stress of active and passive tendon in the form of an exponential function of the natural logarithm base. The exponent of this function contained a number of factors related to the material of belt and pulleys. For the...

  5. The Migration Characteristics of Strong Earthquakes on the North-South Seismic Belt and Its Relation with the South Asia Seismic Belt

    Institute of Scientific and Technical Information of China (English)

    Wang Yipeng; Ma Jin; Li Chuanyou

    2008-01-01

    Migration of strong earthquakes (M≥7.0) along the North-South Seismic Belt of China since 1500 AD shows three patterns: Approximately equal time and distance interval migration from N to S, varied patterns of migration from S to N and grouped strong earthquake activity in a certain period over the entire seismic belt. Analysis of strong earthquakes in the past hundred years shows that the seismicity on the North-South Seismic Belt is also associated with strong earthquake activities on the South Asia Seismic Belt which extends from Myanmar to Sumatra, Indonesia. Strong earthquakes on the former belt often lag several months or years behind the quakes occurring on the later belt. So, after the occurrence of the December 26, 2004 M8.7 great earthquake off the western coast of Sumatra, Indonesia, the possibility of occurrence of strong earthquakes on the North-South Seismic Belt of China cannot be ignored. The above-mentioned migration characteristics of strong earthquakes are related to the northeastward collision and subduction of the India Plate as well as the interaction between the Qinghai-Xizang (Tibet) Plateau and the stable and hard Ordos and Alashan Massifs at its northeastern margin.

  6. Mechanics of Cutting and Boring. Part 3. Kinematics of Continuous Belt Machines,

    Science.gov (United States)

    BOREHOLES, * CUTTING TOOLS , *ICE PENETRATION, *DRILLING MACHINES, *ROAD BUILDING EQUIPMENT, KINEMATICS, PERFORMANCE(ENGINEERING), ROCK, BELTS, EXCAVATION, ARCTIC REGIONS, PERMAFROST, SHALE, SAWS, TRENCHING.

  7. «Granulite» zircons of the Lapland granulite belt

    Science.gov (United States)

    Kaulina, T.

    2003-04-01

    An age of the main stage of granulite metamorphism, which followed the overthrusting of the Lapland granulite belt (LGB) is estimated at about 1.91-1.95 Ga (Tugarinov, Bibikova, 1980; Bernard-Griffiths et al., 1984; Bibikova et al., 1993; Mitrofanov et al., 1993). This high-grade metamorphism is dated by U-Pb method on short prismatic gem-quality zircons that are typical for granulites and are interpreted as formed under stress and space-shortage conditions of the high pressure. And the common belief is that these zircon ages are dating the peak conditions of a metamorphic P-T path, since zircon has a high closure temperature of its U-Pb system. We studied rocks with different degree of metamorphism from Yavr and Pados rivers district (Kola Peninsula, Russia) located in the connection zone of the Tanaelv belt and LGB. Samples from the Tanaelv belt were taken from: 1) leucocratic garnet-clinopyroxene-amphibole plagiogneiss, chemically corresponds to andesite and formed under amphibolite facies 2) leucocratic biotite-pyroxene plagiogneiss with mineral association of granulite facies. Lapland granulites are represented by sillimanite-garnet-biotite gneiss from khondalite complex and leuco-mesocratic amphibole-pyroxene-plagioschist, belonging to the charnockite complex. Metamorphic zircons in all studied samples are represented practically by crystals of the same image. These are round or isometric (rarely subidiomorphic-prismatic in mafic granulites) large crystals with bright luster and high transparency. They are colorless or weakly colored into yellowish-pinkish tones. Crystals are zoneless but may contain cores, especially zircons from khondalite, 60% of which contain zoned cores. Thus typically “granulitic” zircon, described in many works, is the dominant type both in granulites of the Lapland belt and in amphiboles gneisses of the Tanaelv belt. Zircons are distinguished by low U contents (up to 100 ppm) and high Th/U and Zr/Hf ratios (0.6-0.7 and 42

  8. Origin of the Asteroid Belt and Mars' Small Mass

    Science.gov (United States)

    Walsh, Kevin J.; Morbidelli, A.; Raymond, S. N.; O'Brien, D. P.; Mandell, A.

    2010-10-01

    Reproducing the small mass of Mars is a major problem for modern simulations of terrestrial planet accretion (Raymond et al. 2009). Terrestrial planet formation simulations using a planetesimal disk with an outer edge at 1.0 AU have been found to form good Mars analogs (Hansen et al. 2009). However, these initial conditions appear inconsistent with solar system evolution and the asteroid belt. Hydrodynamical simulations show that the evolution of Jupiter and Saturn in a gas-disk generically leads to a two-stage, inward-then-outward migration (Masset & Snellgrove 2001, Morbidelli & Crida 2007, Pierens & Nelson 2008). We present simulations showing that if Jupiter's minimal orbital radius was 1.5 AU, this evolution both truncates the planetesimal disk at 1.0 AU and repopulates the asteroid belt from two distinct parent populations. Our model links the origin of the inner solar system - explaining both the mass of Mars and the properties of the asteroid belt - to a realistic evolution of the giant planets. This scenario represents a paradigm shift in our understanding of the early evolution of the inner solar system. Previously S- and C-type asteroids were thought to have both originated in the 2--3 AU region, with comets forming far away beyond the giant planets. This posed problems in explaining the vast physical differences between S- and C-type asteroids, and the physical similarities between comets and C-type asteroids as shown by Stardust and micrometeorite samples (Brownlee et al. 2006, Gounelle et al. 2008). Our presented scenario finds that S-types likely formed in the 1--3 AU region, with C-types and comets forming in the outer regions of the disk. This provides a much better qualitative explanation of the observed differences and similarities. This work is part of the Helmholtz Alliances "Planetary Evolution and Life", which KJW and AM thank for financial support.

  9. Extensive Admixture and Selective Pressure Across the Sahel Belt.

    Science.gov (United States)

    Triska, Petr; Soares, Pedro; Patin, Etienne; Fernandes, Veronica; Cerny, Viktor; Pereira, Luisa

    2015-11-26

    Genome-wide studies of African populations have the potential to reveal powerful insights into the evolution of our species, as these diverse populations have been exposed to intense selective pressures imposed by infectious diseases, diet, and environmental factors. Within Africa, the Sahel Belt extensively overlaps the geographical center of several endemic infections such as malaria, trypanosomiasis, meningitis, and hemorrhagic fevers. We screened 2.5 million single nucleotide polymorphisms in 161 individuals from 13 Sahelian populations, which together with published data cover Western, Central, and Eastern Sahel, and include both nomadic and sedentary groups. We confirmed the role of this Belt as a main corridor for human migrations across the continent. Strong admixture was observed in both Central and Eastern Sahelian populations, with North Africans and Near Eastern/Arabians, respectively, but it was inexistent in Western Sahelian populations. Genome-wide local ancestry inference in admixed Sahelian populations revealed several candidate regions that were significantly enriched for non-autochthonous haplotypes, and many showed to be under positive selection. The DARC gene region in Arabs and Nubians was enriched for African ancestry, whereas the RAB3GAP1/LCT/MCM6 region in Oromo, the TAS2R gene family in Fulani, and the ALMS1/NAT8 in Turkana and Samburu were enriched for non-African ancestry. Signals of positive selection varied in terms of geographic amplitude. Some genomic regions were selected across the Belt, the most striking example being the malaria-related DARC gene. Others were Western-specific (oxytocin, calcium, and heart pathways), Eastern-specific (lipid pathways), or even population-restricted (TAS2R genes in Fulani, which may reflect sexual selection).

  10. Triggering Sublimation-driven Activity of Main Belt Comets

    Science.gov (United States)

    Haghighipour, N.; Maindl, T. I.; Schäfer, C.; Speith, R.; Dvorak, R.

    2016-10-01

    It has been suggested that the comet-like activity of main belt comets (MBCs) is due to the sublimation of sub-surface water–ice that has been exposed as a result of their surfaces being impacted by meter-sized bodies. We have examined the viability of this scenario by simulating impacts between meter-sized and kilometer-sized objects using a smooth particle hydrodynamics approach. Simulations have been carried out for different values of the impact velocity and impact angle, as well as different target material and water-mass fractions. Results indicate that for the range of impact velocities corresponding to those in the asteroid belt, the depth of an impact crater is slightly larger than 10 m, suggesting that if the activation of MBCs is due to the sublimation of sub-surface water–ice, this ice has to exist no deeper than a few meters from the surface. Results also show that ice exposure occurs in the bottom and on the interior surface of impact craters, as well as on the surface of the target where some of the ejected icy inclusions are re-accreted. While our results demonstrate that the impact scenario is indeed a viable mechanism to expose ice and trigger the activity of MBCs, they also indicate that the activity of the current MBCs is likely due to ice sublimation from multiple impact sites and/or the water contents of these objects (and other asteroids in the outer asteroid belt) is larger than the 5% that is traditionally considered in models of terrestrial planet formation, providing more ice for sublimation. We present the details of our simulations and discuss their results and implications.

  11. DREAM3D simulations of inner-belt dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Cunningham, Gregory Scott [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-05-26

    A 1973 paper by Lyons and Thorne explains the two-belt structure for electrons in the inner magnetosphere as a balance between inward radial diffusion and loss to the atmosphere, where the loss to the atmosphere is enabled by pitch-angle scattering from Coulomb and wave-particle interactions. In the 1973 paper, equilibrium solutions to a decoupled set of 1D radial diffusion equations, one for each value of the first invariant of motion, μ, were computed to produce the equilibrium two-belt structure. Each 1D radial diffusion equation incorporated an L-and μ-dependent `lifetime' due to the Coulomb and wave-particle interactions. This decoupling of the problem is appropriate under the assumption that radial diffusion is slow in comparison to pitch-angle scattering. However, for some values of μ and L the lifetime associated with pitch-angle scattering is comparable to the timescale associated with radial diffusion, suggesting that the true equilibrium solutions might reflect `coupled modes' involving pitch-angle scattering and radial diffusion and thus requiring a 3D diffusion model. In the work we show here, we have computed the equilibrium solutions using our 3D diffusion model, DREAM3D, that allows for such coupling. We find that the 3D equilibrium solutions are quite similar to the solutions shown in the 1973 paper when we use the same physical models for radial diffusion and pitch-angle scattering from hiss. However, we show that the equilibrium solutions are quite sensitive to various aspects of the physics model employed in the 1973 paper that can be improved, suggesting that additional work needs to be done to understand the two-belt structure.

  12. The eastern Central Asian Orogenic Belt: formation and evolution

    Science.gov (United States)

    Xu, Bei; Xu, Wenliang

    2017-08-01

    The Central Asian Orogenic Belt (CAOB) extends from the northern Eurasian continent in the west via Mongolia, Inner Mongolia and northeast part of China to the Russia Far East in the east. It is characterized by complex trench-arc-basin subduction system, exotic terrane (microcontinents) accretion, massive generation of juvenile crust during the Neoproterozoic-Phanerozoic (e.g., Jahn et al., 2000, 2004; Sengör et al., 1993). A lot of papers about formation and evolution of the CAOB have been published and new field observations and geochemical data for key areas of the CAOB challenge to previous assessments. Several areas previously defined as juvenile are now shown to have mixed crustal compositions. For example, Kröner et al. (2014, in press) estimated that the distribution of various crustal provinces is truly juvenile crustal material ca. 20%, mixed crust ca. 30%, old crust ca. 50%,respectively, in the CAOB, similar to those in other accretionary orogens through Earth history. A two-stage model for the evolution of the CAOB has been suggested based on recent data from the Eastern Tianshan and Beishan (Gao et al., 2011; Su et al., 2011; Chen et al., 2016; Wang et al., 2017), which suggests the process of the formation and evolution of the CAOB includes closure of the Paleo Asian ocean (PAO), formation of orogenic belt before the late Paleozoic and crustal extension and magmatism resulted from plume upon the young orogenic belt after the late Paleozoic. This new model changes previous concept that the CAOB developed through the Paleozoic and is supported by recent researches on the eastern CAOB.

  13. Event-Specific Quantification of Radiation Belt Radial Diffusion

    Science.gov (United States)

    Tu, W.; Sarris, T. E.; Ozeke, L.

    2016-12-01

    Recently, there has been a great emphasis on developing event-specific inputs for radiation belt models, since they are proven critical for reproducing the observed radiation belt dynamics during strong events. For example, our DREAM3D simulation of the 8-9 October 2012 storm demonstrates that event-specific chorus wave model and seed population are critical to reproduce the strong enhancement of MeV electrons in this event. However, the observed fast electron dropout preceding the enhancement was not captured by the simulation, which could be due to the combined effects of fast outward radial diffusion of radiation belt electrons with magnetopause shadowing and enhanced electron precipitation. Without an event-specific quantification of radial diffusion, we cannot resolve the relative contribution of outward radial diffusion and precipitation to the observed electron dropout or realistically reproduce the dynamics during the event. In this work, we provide physical quantification of radial diffusion specific to the October 2012 event by including both real-time and global distributions of ULF waves from a constellation of wave measurements and event-specific estimation of ULF wave mode structure. The global maps of ULF waves during the event are constructed by combining the real-time measurements from the Van Allen Probes, THEMIS, and GOES satellites in space and a large array of ground magnetometers. The real-time ULF wave mode structure is then estimated using the new Cross-Wavelet Transform technique, applied to various azimuthally aligned pairs of ULF wave measurements that are located at the same L shells. The cross power and phase differences between the time series are calculated using the technique, based on which the wave power per mode number is estimated. Finally, the physically estimated radial diffusion coefficients specific to the event are applied to the DREAM3D model to quantify the relative contribution of radial diffusion to the electron dynamics

  14. Collisions and drag in debris discs with eccentric parent belts

    Science.gov (United States)

    Löhne, T.; Krivov, A. V.; Kirchschlager, F.; Sende, J. A.; Wolf, S.

    2017-08-01

    Context. High-resolution images of circumstellar debris discs reveal off-centred rings that indicate past or ongoing perturbation, possibly caused by secular gravitational interaction with unseen stellar or substellar companions. The purely dynamical aspects of this departure from radial symmetry are well understood. However, the observed dust is subject to additional forces and effects, most notably collisions and drag. Aims: To complement the studies of dynamics, we therefore aim to understand how the addition of collisional evolution and drag forces creates new asymmetries and strengthens or overrides existing ones. Methods: We augmented our existing numerical code Analysis of Collisional Evolution (ACE) by an azimuthal dimension, the longitude of periapse. A set of fiducial discs with global eccentricities ranging from 0 to 0.4 was evolved over gigayear timescales. Size distribution and spatial variation of dust were analysed and interpreted. We discuss the basic impact of belt eccentricity on spectral energy distributions and images. Results: We find features imposed on characteristic timescales. First, radiation pressure defines size cut-offs that differ between periapse and apoapse, resulting in an asymmetric halo. The differences in size distribution make the observable asymmetry of the halo depend on wavelength. Second, collisional equilibrium prefers smaller grains on the apastron side of the parent belt, reducing the effect of pericentre glow and the overall asymmetry. Third, Poynting-Robertson drag fills the region interior to an eccentric belt such that the apastron side is more tenuous. Interpretation and prediction of the appearance in scattered light is problematic when spatial and size distribution are coupled.

  15. BAOBAB (Big And Outrageously Bold Asteroid Belt) Project

    Science.gov (United States)

    Mcfadden, L. A.; Thomas, C. A; Englander, J. A.; Ruesch, O.; Hosseini, S.; Goossens, S. J.; Mazarico, E. M.; Schmerr, N.

    2017-01-01

    One of the intriguing results of NASA's Dawn mission is the composition and structure of the Main Asteroid Belt's only known dwarf planet, Ceres [1]. It has a top layer of dehydrated clays and salts [2] and an icy-rocky mantle [3,4]. It is widely known that the asteroid belt failed to accrete as a planet by resonances between the Sun and Jupiter. About 20-30 asteroids >100 km diameter are probably differentiated protoplanets [5]. 1) how many more and which ones are fragments of protoplanets? 2) How many and which ones are primordial rubble piles left over from condensation of the solar nebula? 3) How would we go about gaining better and more complete characterization of the mass, interior structure and composition of the Main Belt asteroid population? 4) What is the relationship between asteroids and ocean worlds? Bulk parameters such as the mass, density, and porosity, are important to characterize the structure of any celestial body, and for asteroids in particular, they can shed light on the conditions in the early solar system. Asteroid density estimates exist but currently they are often based on assumed properties of taxonomic classes, or through astronomical survey data where interactions with asteroids are weak at best resulting in large measurement uncertainty. We only have direct density estimates from spacecraft encounters for a few asteroids at this time. Knowledge of the asteroids is significant not only to understand their role in solar system workings, but also to assess their potential as space resources, as impact hazards on Earth, or even as harboring life forms. And for the distant future, we want to know if the idea put forth in a contest sponsored by Physics Today, to surface the asteroids into highly reflecting, polished surfaces and use them as a massively segmented mirror for astrophysical exploration [6], is feasible.

  16. Geological evolution of the Neoproterozoic Bemarivo Belt, northern Madagascar

    Science.gov (United States)

    Thomas, Ronald J.; De Waele, B.; Schofield, D.I.; Goodenough, K.M.; Horstwood, M.; Tucker, R.; Bauer, W.; Annells, R.; Howard, K. J.; Walsh, G.; Rabarimanana, M.; Rafahatelo, J.-M.; Ralison, A.V.; Randriamananjara, T.

    2009-01-01

    The broadly east-west trending, Late Neoproterozoic Bemarivo Belt in northern Madagascar has been re-surveyed at 1:100 000 scale as part of a large multi-disciplinary World Bank-sponsored project. The work included acquisition of 14 U-Pb zircon dates and whole-rock major and trace element geochemical data of representative rocks. The belt has previously been modelled as a juvenile Neoproterozoic arc and our findings broadly support that model. The integrated datasets indicate that the Bemarivo Belt is separated by a major ductile shear zone into northern and southern "terranes", each with different lithostratigraphy and ages. However, both formed as Neoproterozoic arc/marginal basin assemblages that were translated southwards over the north-south trending domains of "cratonic" Madagascar, during the main collisional phase of the East African Orogeny at ca. 540 Ma. The older, southern terrane consists of a sequence of high-grade paragneisses (Sahantaha Group), which were derived from a Palaeoproterozoic source and formed a marginal sequence to the Archaean cratons to the south. These rocks are intruded by an extensive suite of arc-generated metamorphosed plutonic rocks, known as the Antsirabe Nord Suite. Four samples from this suite yielded U-Pb SHRIMP ages at ca. 750 Ma. The northern terrane consists of three groups of metamorphosed supracrustal rocks, including a possible Archaean sequence (Betsiaka Group: maximum depositional age approximately 2477 Ma) and two volcano-sedimentary sequences (high-grade Milanoa Group: maximum depositional age approximately 750 Ma; low grade Daraina Group: extrusive age = 720-740 Ma). These supracrustal rocks are intruded by another suite of arc-generated metamorphosed plutonic rocks, known as the Manambato Suite, 4 samples of which gave U-Pb SHRIMP ages between 705 and 718 Ma. Whole-rock geochemical data confirm the calc-alkaline, arc-related nature of the plutonic rocks. The volcanic rocks of the Daraina and Milanoa groups also

  17. Rapid energization of radiation belt electrons by nonlinear wave trapping

    Directory of Open Access Journals (Sweden)

    Y. Katoh

    2008-11-01

    Full Text Available We show that nonlinear wave trapping plays a significant role in both the generation of whistler-mode chorus emissions and the acceleration of radiation belt electrons to relativistic energies. We have performed particle simulations that successfully reproduce the generation of chorus emissions with rising tones. During this generation process we find that a fraction of resonant electrons are energized very efficiently by special forms of nonlinear wave trapping called relativistic turning acceleration (RTA and ultra-relativistic acceleration (URA. Particle energization by nonlinear wave trapping is a universal acceleration mechanism that can be effective in space and cosmic plasmas that contain a magnetic mirror geometry.

  18. Ultra low frequency waves impact on radiation belt energetic particles

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    One of the most fundamental important issues in the space physics is to understand how solar wind energy transports into the inner magnetosphere.Ultra low frequency(ULF)wave in the magnetosphere and its impact on energetic particles,such as the wave-particle resonance,modulation,and particle acceleration,are extremely important topics in the Earth’s radiation belt dynamics and solar wind― magnetospheric coupling.In this review,we briefly introduce the recent advances on ULF waves study. Further,we will explore the density structures and ion compositions around the plasmaspheric boundary layer(PBL)and discuss its possible relation to the ULF waves.

  19. Ultra low frequency waves impact on radiation belt energetic particles

    Institute of Scientific and Technical Information of China (English)

    ZONG QiuGang; HAO YongQiang; WANG YongFu

    2009-01-01

    One of the most fundamental important issues in the space physics is to understand how solar wind energy transports into the inner magnetosphere.Ultra low frequency(ULF)wave in the magnetosphere and its impact on energetic particles,such as the wave-particle resonance,modulation,and particle acceleration,are extremely important topics in the Earth's radiation belt dynamics and solar windmagnetospheric coupling.In this review,we briefly introduce the recent advances on ULF waves study.Further,we will explore the density structures and ion compositions around the plasmaspheric boundary layer(PBL)and discuss its possible relation to the ULF waves.

  20. The radiation belt origin of Uranus' nightside radio emission

    Science.gov (United States)

    Curtis, S. A.; Desch, M. D.; Kaiser, M. L.

    1987-01-01

    On the basis of the location of the source field lines of the smooth nightside component of Uranus kilometric radiation, the most likely free energy source is the outer radiation belts. As the terminator sweeps over the magnetic north polar region, precipitation of electrons generated by solar heating of the upper atmosphere and submergence of the electron mirror points deeper in the atmosphere will create a backscattered electron distribution with an enhanced population at large pitch angles. The clocklike radio emission turns out to be a direct consequence of the terminator's control of the emission process.

  1. Wave-particle interactions in the outer radiation belts

    CERN Document Server

    Agapitov, O V; Artemyev, A V; Mourenas, D; Krasnoselskikh, V V

    2015-01-01

    Data from the Van Allen Probes have provided the first extensive evidence of non-linear (as opposed to quasi-linear) wave-particle interactions in space with the associated rapid (fraction of a bounce period) electron acceleration to hundreds of keV by Landau resonance in the parallel electric fields of time domain structures (TDS) and very oblique chorus waves. The experimental evidence, simulations, and theories of these processes are discussed. {\\bf Key words:} the radiation belts, wave-particle interaction, plasma waves and instabilities

  2. A New Perspective on Trapped Radiation Belts in Planetary Atmospheres

    Science.gov (United States)

    Diaz, A.; Lodhi, M. A. K.; Wilson, T. L.

    2005-01-01

    The charged particle fluxes trapped in the magnetic dipole fields of certain planets in our Solar System are interesting signatures of planetary properties in space physics. They also represent a source of potentially hazardous radiation to spacecraft during planetary and interplanetary exploration. The Earth s trapped radiation belts have been studied for years and the physical mechanisms by which primary radiation from the Sun and Galaxy is captured is well understood. The higher-energy particles collide with molecules in the planetary atmosphere and initiate large cascades of secondary radiation which itself becomes trapped by the magnetic dipole field of the planet. Some of it is even backscattered as albedo neutrons.

  3. Determination of Flutter Derivatives for the Great Belt Bridge

    DEFF Research Database (Denmark)

    Poulsen, Niels Kjølstad; Damsgaard, Aage; Reinhold, Thim A.

    1992-01-01

    A new method which combines control theory and system identification techniques has been used to extract flutter derivatives from section model tests for the Great Belt East Bridge. Tests were conducted by exciting the section model simultaneously in vertical and torsional modes of vibration. Tests...... coupled motion derivatives from a simple set of tests.This paper describes the control theory and system identification approach used and discusses the limitations encountered. Results are compared with flutter derivatives obtained by other researchers. The method offers a reasonably robust technique...

  4. Novel Solution for Leg Motion with 5-Link Belt Mechanism

    Science.gov (United States)

    E. Ch., Lovasz; Pop, C.; Pop, F.; Dolga, V.

    2014-11-01

    From the analysis of Theo Jansen walking mechanism and of the path curve that it describes the reduced capability for crossing over obstacles of the Jansen leg (1 DOF) is pointed out. By using a 5 link belt mechanism with 2 DOF can be adapted for generating similar Jansen mechanism path curve, where the step height of this path can be increased. For this purpose a mathematical model is conceived in order to analyse and determine the parameters for driving and control of the operation of the novel walking leg solution.

  5. Effective Conveyor Belt Inspection for Improved Mining Productivity

    Energy Technology Data Exchange (ETDEWEB)

    David LaRose

    2006-07-01

    This document details progress on the project ''Effective Conveyor Belt Inspection for Improved Mining Productivity'' during the period from November 15, 2005 to May 14, 2006. Highlights include significant improvements in the accuracy and reliability of computer-vision based vulcanized splice detection, deployment of the vulcanized splice detection algorithms for daily use in two working mines, and successful demonstration of an early prototype of a Smart-Camera based system for on-site mechanical splice detection in coal mine installations.

  6. Roll seat belt induced injury of the duodenum.

    Science.gov (United States)

    Bergqvist, D; Hedelin, H

    1976-05-01

    A case of duodenal rupture with a roll three-point seatbelt is described. It is apparently the seventh reported case of duodenal rupture in safety belt users. A female driver fell asleep, and her car went off the road, rolling forward in a ditch, slowing slightly, and then came to a sudden stop. The rupture was unusual: on the first part of duodenum, intraperitoneal, and longitudinal. The rupture mechanism is discussed, and the deficiencies of the roll seatbelt pointed out in accidents like the one described.

  7. Single beam optical conveyor belt for chiral particles

    CERN Document Server

    Fernandes, David E

    2016-01-01

    We propose a novel paradigm to selectively manipulate and transport small engineered chiral particles and discriminate different enantiomers using unstructured chiral light. It is theoretically shown that the response of a chiral metamaterial particle may be tailored to enable an optical conveyor belt operation with no optical traps, such that for a fixed incident light helicity and independent of the nanoparticle location, it is either steadily pushed towards the direction of the photon flow or steadily pulled against the photon flow. Our findings create new opportunities for unconventional optical manipulations of tailored nanoparticles and may have applications in sorting racemic mixtures of artificial chiral molecules and in particle delivery.

  8. GCR as a source for Inner radiation belt of Saturn.

    Science.gov (United States)

    Kotova, A.; Roussos, E.; Krupp, N.; Dandouras, I. S.

    2014-12-01

    During the insertion orbit of Cassini in 2004 the Ion and Neutron Camera measured significant fluxes of the energetic neutral atoms (ENA) coming from the area between the D-ring and the Saturn's atmosphere, what brought up the idea of the possible existence of the innermost radiation belt in this narrow gap (1). There are two main sources of energetic charged particles for such inner radiation belt: the interaction of the Galactic Cosmic Rays (GCR) with the Saturn's atmosphere and rings, which due to CRAND process can produce the keV-MeV ions or electrons in the region, and the double charge exchange of the ENAs, coming from the middle magnetosphere, what can bring the keV ions to the region of our interest. Using the particles tracer, which was developed in our group, and GEANT4 software, we study in details those two processes. With a particle tracer we evaluate the GCR access to the Saturn atmosphere and rings. Simulation of the GCR trajectories allows to calculate the energy spectra of the arriving energetic particles, which is much more accurate, compare to the analytically predicted spectra using the Stoermer theory, since simulation includes effects of the ring shadow and non-dipolar processes in the magnetosphere. Using the GEANT4 software the penetration of the GCR through the matter of rings was simulated, and the production of secondaries particles was estimated. Finally, the motion of secondaries was simulated using the particles tracer, and evaluation of the energy spectrum of neutrons the decay of which leads to the production of final CRAND elements in the inner Saturnian radiation belts was done. We show that for inner radiation belt most energetic ions comes from GCR interaction with rings, it's penetration and from interaction of secondaries with Saturn's atmosphere. This simulation allows us to predict the fluxes of energetic ions and electrons, which particle detector MIMI/LEMMS onboard the Cassini can measure during the so-called "proximal

  9. Crustal Development in the Northeast Asian Orogenic Belt and its comparison with the Central Asian Orogenic Belt

    Science.gov (United States)

    Jahn, Bor-ming

    2016-04-01

    The Northeast Asian Orogenic Belt is a Mesozoic-Cenozoic accretionary orogenic collage, and it constitutes the northern and principal part of the "Nipponides" (Sengor and Natal'in, 1996). The tectonic framework was formed in Mesozoic and Cenozoic, and it continues to evolve along the modern Pacific arc-trench systems. Generally, a oceanward younging of tectonic units may be discerned, but such a simple pattern is disrupted in many places by extensive strike-slip faulting, most of which is left-lateral. In this talk, the issue of crustal development in the sector of Sikhote-Alin and Japanese Islands will be discussed based on the geochemical and isotopic analyses of granitoids that intruded in various tectonostratigraphic terrains. The majority of granitoids in the NE Asian Orogenic Belt formed from Jurassic to late Cenozoic, with Cretaceous as the dominant period of granitic magmatism and tectonothermal events. A few Early Paleozoic granitic rocks (500 to 450 Ma) have been identified in SW Japan (Kurosegawa Belt) as well as in NE Japan (Kitakami Belt), among them the ca. 500 Ma diorites and tonalites of southern Kitakami are the oldest rocks in Japan and interpreted as the first TTG crust of proto-Japan (Isozaki et al., 2015). Cretaceous granitoids are widespread in Sikhote-Alin and in NE and SW Japan. However, granitoids were emplaced only in the Cenozoic in Sakhalin (ca. 44 - 42 Ma) and Hokkaido (45, 37 and 18 Ma). Most granitoids from Sikhote-Alin are of I-type and have ISr = 0.7040 to 0.7083, and ɛNd(T) = +3.0 to -6.0 (mostly 0 to -5). The Sr-Nd isotopic data fall within the range of granitoids from SW Japan (0.704 to 0.712; +5.0 to -13.0), and the data of Cretaceous granitoids from Sikhote-Alin and SW Japan overlap almost completely. The Cenozoic granitoids of Hokkaido are characterized by ISr = 0.7044 - 0.7061, ɛNd(T) = +1.0 to +4.7, and Sm-Nd model-1 ages = 400-1000 Ma. This is remarkably similar to the Sakhalin granitoids with ISr = 0.7047 - 0.7050,

  10. Mixed brittle-plastic deformation behaviour in a slate belt. Examples from the High-Ardenne slate belt (Belgium, Germany)

    Science.gov (United States)

    Sintubin, Manuel; van Baelen, Hervé; van Noten, Koen; Muchez, Philippe

    2010-05-01

    In the High-Ardenne slate belt, part of the Rhenohercynian external fold-and-thrust belt at the northern extremity of the Late Palaeozoic Variscan orogen (Belgium, Germany, France), particular quartz vein occurrences can be observed in predominantly fine-grained siliciclastic metasediments. Detailed structural, petrographical and geochemical studies has revealed that these vein occurrences can be related to a mixed brittle-plastic deformation behaviour in a low-grade metamorphic mid-crustal environment. The first type of quartz veins are bedding-perpendicular, lens-shaped extension veins that are confined to the sandstone layers within the multilayer sequence. Fluid inclusion studies demonstrate high fluid pressures suggesting that the individual sandstone bodies acted as isolated high-pressure compartments in an overpressured basin. Hydraulic fracturing occurred during the tectonic inversion (from extension to compression) in the earliest stages of the Variscan orogeny. The vein fill shows a blocky character indicating crystal growth in open cavities. Both the typical lens shape of the veins and the subsequent cuspate-lobate folding of the bed interfaces in between the quartz veins suggest plastic deformation of cohesionless fluid-filled fissures. Metamorphic grade of the host rock and fluid temperature and pressure clearly indicates mid-crustal conditions below the brittle-plastic transition. This first type of quartz veins exemplifies mixed brittle-plastic deformation behaviour, possibly related to a transient deepening of the brittle-plastic transition. This is in contrast with contemporaneous bedding-perpendicular crack-seal veins observed in higher - upper-crustal - structural levels in the slate belt, reflecting pure brittle deformation behaviour. The second type are discordant quartz veins confined to extensional low-angle detachment shear zones. These very irregular veins transect a pre-existing pervasive cleavage fabric. They show no matching walls and

  11. Interlimb Coordination during Tied-Belt and Transverse Split-Belt Locomotion before and after an Incomplete Spinal Cord Injury.

    Science.gov (United States)

    Thibaudier, Yann; Hurteau, Marie-France; Dambreville, Charline; Chraibi, Anass; Goetz, Laurent; Frigon, Alain

    2017-05-01

    Coordination between the arms/forelimbs and legs/hindlimbs is often impaired in humans and quadrupedal mammals after incomplete spinal cord injury. In quadrupeds, the forelimbs often take more steps than the hindlimbs, producing a two-to-one forelimb-hindlimb (2-1 FL-HL) coordination. In locomotor performance scales, this is generally considered a loss of FL-HL coordination. Here, FL-HL coordination was quantified before and 8 weeks after a lateral spinal hemisection at the sixth thoracic segment in six adult cats. Cats were tested during tied-belt locomotion (equal front and rear speeds) and transverse split-belt locomotion with the forelimbs or hindlimbs stepping faster. The results show that consistent phasing between forelimb and hindlimb movements was maintained after hemisection, even with the appearance of 2-1 FL-HL coordination, indicating that new stable forms of coordination emerge. Moreover, transverse split-belt locomotion potently modulated interlimb coordination and was capable of restoring a one-to-one FL-HL coordination with a faster treadmill speed for the hindlimbs. In conclusion, the results suggest that neural communication persists after an incomplete spinal cord injury, despite an unequal number of steps between the forelimbs and hindlimbs, and that interlimb coordination can be modulated by having the forelimbs or hindlimbs move at a faster frequency. We propose that locomotor recovery scales incorporate more sensitive methods to quantify FL-HL coordination, to better reflect residual functional capacity and possible cervicolumbar neural communication. Lastly, devising training protocols that make use of the bidirectional influences of the cervical and lumbar locomotor pattern generators could strengthen interlimb coordination and promote locomotor recovery.

  12. RESEARCH OF DEPENDENCE OF BELT CONVEYER DRIVE POWER ON ITS DESIGN PARAMETERS

    Directory of Open Access Journals (Sweden)

    V. M. Bohomaz

    2016-02-01

    Full Text Available Purpose. A drive is one of the basic elements of belt conveyers. To determine the drive power it is necessary to conduct calculations by standard methodologies expounded in modern technical literature. Such calculations demand a fair amount of time. The basic design parameters of a belt conveyer include type of load, design efficiency, geometrical dimensions and path configuration, operation conditions. The article aims to build the parametric dependence of belt conveyer drive power on its design parameters, that takes into account standard dimensions and parameters of belts, idlers and pulleys. Methodology. The work examines a belt conveyer with two areas: sloping and horizontal. Using the methodology for pulling calculation by means of belt conveyer encirclement, there are built parametric dependences of pull forces in the characteristic conveyer path points on the type of load, design efficiency, geometrical dimensions and path configuration, operation conditions. Findings. For the belt conveyers of the considered type there are built parametric dependences of drive power on type of load, design efficiency, geometrical dimensions and path configuration, operation conditions, taking into account the belt standard dimensions and corresponding assumptions in relation to idler and pulley types. Originality.This is the first developed parametric dependence of two-area (sloping and horizontal belt conveyer drive power on type of load, design efficiency, geometrical dimensions and path configuration, operation conditions that takes into account standard dimensions and parameters of belts, idlers and pulleys. Practical value. Use of the built drive power dependences on design parameters for the belt conveyers with sloping and horizontal areas gives an opportunity of relatively rapid determination of drive power approximate value at the design stage. Also it allows quality selection of its basic elements at specific design characteristics and

  13. Main-Belt Comet P/2008 R1 (Garradd)

    CERN Document Server

    Jewitt, David; Haghighipour, Nader

    2009-01-01

    We present a study of the newly-discovered main-belt comet P/2008 R1 (Garradd), an object with the dynamical characteristics of an asteroid and the physical characteristics of a comet. Photometry sets a limit to the effective radius of the nucleus at r_e < 0.7 km (red geometric albedo 0.05 assumed). The coma shows a secular fading in our data caused by the escape of dust particles from the near-nucleus environment. The optical reflection spectrum is a nearly neutral continuum devoid of gaseous emission lines, from which we derive a limit to the cyanide (CN) radical production rate of Q_CN <1.4e23/s and infer a mass loss rate <1.5 kg/s at the time of our observations. Unlike the first-reported main-belt comets, P/2008 R1 is not dynamically stable. The nearby 8:3 mean-motion resonance with Jupiter induces dynamical instability on timescales 20 to 30 Myr. Hence, we conclude that P/2008 R1 has recently arrived from a more stable source elsewhere. The high Tisserand parameter of the orbit (in fact, with T...

  14. Phillips solves Venezuelan tar-belt producing problems

    Energy Technology Data Exchange (ETDEWEB)

    Finken, R.E.; Meldau, R.F.

    1972-07-17

    Phillips Petroleum Co. and partners have just completed an expansion to produce, treat, and ship 88,000 bpd of heavy oil from the tar-belt region of E. Venezuela. The first phase of the expansion was a $4.5-million diluent project to produce 80 API oil from the largest reservoir in the Morichal field, Monagas State. The second phase was to drill 41 wells in Amoco's Jobo field under an operating contract. The final phase was a $3.5-million expansion of treating, pipeline, and terminal facilities to handle the increased throughput. The crude produced is naphthenic and after treating is ready for road-building use, and as residual fuel at its usual viscosity of 520 to 550 sfs at 122/sup 0/F. As an asphalt stock, it has a yield of 60 to 70% and is readily processed into quality-paving asphalts which meet standard specifications. Production of the viscous 80 API crude oil, even though the major oil reservoir in Morichal, was very limited until installation of the diluent facilities last year. The same problem exists all over the famous tar-belt region of E. Venezuela. Vast oil reserves exist almost continuously in the area shown by the base map, but the oil cannot be dehydrated, desalted or transported when produced by itself. Thus, the 80 API oil is a known reserve, but without an external supply of diluent it cannot be commercially recovered.

  15. Producing 88,000 bd. in the tar belt

    Energy Technology Data Exchange (ETDEWEB)

    Finken, R.E.; Meldau, R.F.

    1972-08-01

    The Phillips Petroleum Co. and its associates have completed the necessary work for producing, treating and transporting 88,000 bopd of crude oil from the Oil Belt of the Orinoco, in the E. part of Venezuela. The first step consisted in assembling the means for diluting the 8$ API crude, coming from the producing horizons of the Morichal field. The second step was the drilling of 41 wells in the Jobo field. The final step consisted in the upgrading of the means of treatment, the pipelining and equipment for handling the increased production. The solvent which is used to dilute the heavy crude comes to the port by tanker and is pumped through a new pipeline to the field, where distribution lines take it to the various wells. Here it is pumped down the tubing to a point above the pump (which is located above a production packer) and then out the annulus. During this cycle the heavy crude is diluted with the light solvent to a consistency where it is manageable. The producing sands of the Tar Belt have a reserve estimate of 700-billion barrels of recoverable oil. Phillips also makes extensive use of thermal recovery methods in producing these wells.

  16. Nano-optical conveyor belt with waveguide-coupled excitation.

    Science.gov (United States)

    Wang, Guanghui; Ying, Zhoufeng; Ho, Ho-pui; Huang, Ying; Zou, Ningmu; Zhang, Xuping

    2016-02-01

    We propose a plasmonic nano-optical conveyor belt for peristaltic transport of nano-particles. Instead of illumination from the top, waveguide-coupled excitation is used for trapping particles with a higher degree of precision and flexibility. Graded nano-rods with individual dimensions coded to have resonance at specific wavelengths are incorporated along the waveguide in order to produce spatially addressable hot spots. Consequently, by switching the excitation wavelength sequentially, particles can be transported to adjacent optical traps along the waveguide. The feasibility of this design is analyzed using three-dimensional finite-difference time-domain and Maxwell stress tensor methods. Simulation results show that this system is capable of exciting addressable traps and moving particles in a peristaltic fashion with tens of nanometers resolution. It is the first, to the best of our knowledge, report about a nano-optical conveyor belt with waveguide-coupled excitation, which is very important for scalability and on-chip integration. The proposed approach offers a new design direction for integrated waveguide-based optical manipulation devices and its application in large scale lab-on-a-chip integration.

  17. Automation of belts; Automatizacion de Cintas de Interior

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

    This document presents the most important aspects, and the results of the project DEVELOPMENT AND COMMISSIONING OF AN INTEGRATED HAULAGE AND VENTILATION CONTROL SYSTEM IN A MINE USING VERY LONG SUBLEVEL-CAVING WINNING METHOD. Project's targets were to develop, implement and commission a distributed control system for underground mining, which should allow the control and optimisation of the whole (continuous) haulage network. It should also integrate statutory safety features required for both winning and haulage. The system is capable of controlling the most common devices used in underground coal mining transport networks, like conveyor belts, armored conveyors, regulation silos, etc. from the winning faces to the surface, and also the interlocks between them. Moreover, the system implements statutory safety functions for conveyor belt operation, and for mining activities carried out in culls de sac. Specifically, for its relationship with the transport system, it should monitor secondary ventilation, fire damp and toxic gases concentration, and mains power presence in the culls de sac, which have already reached a length of 2000 m. The prototype was installed in the mine that Carbones de Pedraforca owns in Saldes, Barcelona. (Author)

  18. Short-Term Forecasting of Radiation Belt and Ring Current

    Science.gov (United States)

    Fok, Mei-Ching

    2007-01-01

    A computer program implements a mathematical model of the radiation-belt and ring-current plasmas resulting from interactions between the solar wind and the Earth s magnetic field, for the purpose of predicting fluxes of energetic electrons (10 keV to 5 MeV) and protons (10 keV to 1 MeV), which are hazardous to humans and spacecraft. Given solar-wind and interplanetary-magnetic-field data as inputs, the program solves the convection-diffusion equations of plasma distribution functions in the range of 2 to 10 Earth radii. Phenomena represented in the model include particle drifts resulting from the gradient and curvature of the magnetic field; electric fields associated with the rotation of the Earth, convection, and temporal variation of the magnetic field; and losses along particle-drift paths. The model can readily accommodate new magnetic- and electric-field submodels and new information regarding physical processes that drive the radiation-belt and ring-current plasmas. Despite the complexity of the model, the program can be run in real time on ordinary computers. At present, the program can calculate present electron and proton fluxes; after further development, it should be able to predict the fluxes 24 hours in advance

  19. Ultra-relativistic electrons in Jupiter's radiation belts.

    Science.gov (United States)

    Bolton, S J; Janssen, M; Thorne, R; Levin, S; Klein, M; Gulkis, S; Bastian, T; Sault, R; Elachi, C; Hofstadter, M; Bunker, A; Dulk, G; Gudim, E; Hamilton, G; Johnson, W T K; Leblanc, Y; Liepack, O; McLeod, R; Roller, J; Roth, L; West, R

    2002-02-28

    Ground-based observations have shown that Jupiter is a two-component source of microwave radio emission: thermal atmospheric emission and synchrotron emission from energetic electrons spiralling in Jupiter's magnetic field. Later in situ measurements confirmed the existence of Jupiter's high-energy electron-radiation belts, with evidence for electrons at energies up to 20[?]MeV. Although most radiation belt models predict electrons at higher energies, adiabatic diffusion theory can account only for energies up to around 20[?]MeV. Unambiguous evidence for more energetic electrons is lacking. Here we report observations of 13.8[?]GHz synchrotron emission that confirm the presence of electrons with energies up to 50[?]MeV; the data were collected during the Cassini fly-by of Jupiter. These energetic electrons may be repeatedly accelerated through an interaction with plasma waves, which can transfer energy into the electrons. Preliminary comparison of our data with model results suggests that electrons with energies of less than 20[?]MeV are more numerous than previously believed.

  20. Internal Charging Design Environments for the Earths Radiation Belts

    Science.gov (United States)

    Minow, Joseph I.; Edwards, David L.

    2009-01-01

    Relativistic electrons in the Earth's radiation belts are a widely recognized threat to spacecraft because they penetrate lightly shielded vehicle hulls and deep into insulating materials where they accumulate to sufficient levels to produce electrostatic discharges. Strategies for evaluating the magnitude of the relativistic electron flux environment and its potential for producing ESD events are varied. Simple "rule of thumb" estimates such as the widely used 10(exp 10) e-/sq cm fluence within 10 hour threshold for the onset of pulsing in dielectric materials provide a quick estimate of when to expect charging issues. More sophisticated strategies based on models of the trapped electron flux within the Earth s magnetic field provide time dependent estimates of electron flux along spacecraft orbits and orbit integrate electron flux. Finally, measurements of electron flux can be used to demonstrate mean and extreme relativistic electron environments. This presentation will evaluate strategies used to specify energetic electron flux and fluence environments along spacecraft trajectories in the Earth s radiation belts.

  1. Study of the NWC electrons belt observed on DEMETER Satellite

    CERN Document Server

    Li, Xinqiao; Wang, Ping; Wang, Huanyu; Lu, Hong; Zhang, Xuemin; Huang, Jianping; Shi, Feng; Yu, Xiaoxia; Xu, Yanbing; Meng, Xiangcheng; Wang, Hui; Zhao, Xiaoyun; Parrot, M

    2010-01-01

    We analyzed the data from 2007 to 2008, which is observed by IDP onboard DEMETER satellite, during ten months of NWC working and seven months of NWC shutdown. The characteristic of the space instantaneous electron belts, which come from the influence of the VLF transmitted by NWC, is studied comprehensively. The main distribution region of the NWC electron belts and the flux change are given. We also studied the distribution characteristic of the average energy spectrum in different magnetic shell at the height of DEMETER orbit and the difference of the average energy spectrum of the electrons in the drift loss-cone between day and night. As a result, the powerful power of NWC transmitter and the 19.8 kHz narrow bandwidth VLF emission not only created a momentary electrons enhancement region, which strides 180 degree in them longitude direction and from 1.6 to 1.9 in L value, with the rise of the electrons flux reaching to 3 orders of magnitude mostly, but also induced the enhancement or loss of electrons in ...

  2. The Distribution of Basaltic Asteroids in the Main Belt

    CERN Document Server

    Moskovitz, Nicholas A; Gaidos, Eric; Willman, Mark; Nesvorny, David; Fevig, Ronald; Ivezic, Zeljko

    2008-01-01

    We present the observational results of a survey designed to target and detect asteroids whose colors are similar to those of Vesta family members and thus may be considered as candidates for having a basaltic composition. Fifty basaltic candidates were selected with orbital elements that lie outside of the Vesta dynamical family. Optical and near-infrared spectra were used to assign a taxonomic type to 11 of the 50 candidates. Ten of these were spectroscopically confirmed as V-type asteroids, suggesting that most of the candidates are basaltic and can be used to constrain the distribution of basaltic material in the Main Belt. Using our catalog of V-type candidates and the success rate of the survey, we calculate unbiased size-frequency and semi-major axis distributions of V-type asteroids. These distributions, in addition to an estimate for the total mass of basaltic material, suggest that Vesta was the predominant contributor to the basaltic asteroid inventory of the Main Belt, however scattered planetesim...

  3. V-type asteroids in the middle Main Belt

    CERN Document Server

    Roig, F; Gil-Hutton, R; Lazzaro, D

    2007-01-01

    The recent discovery of the first V-type asteroid in the middle belt, (21238) 1995WV7, located at ~2.54 AU, raises the question of whether it came from (4) Vesta or not. In this paper, we present spectroscopic observations indicating the existence of another V-type asteroid at ~2.53 AU, (40521) 1999RL95, and we investigate the possibility that these two asteroids evolved from the Vesta family to their present orbits by drifting in semi-major axis due to the Yarkovsky effect. The main problem with this scenario is that the asteroids need to cross the 3/1 mean motion resonance with Jupiter, which is highly unstable. Combining numerical simulations of the orbital evolution, that include the Yarkovsky effect, with Monte Carlo models, we compute the probability of an asteroid of given diameter D to evolve from the Vesta family and to cross over the 3/1 resonance, reaching a stable orbit in the middle belt. Our results indicate that an asteroid like (21238) 1995WV7 has a low probability of having evolved through th...

  4. The Collisional Divot in the Kuiper belt Size Distribution

    CERN Document Server

    Fraser, Wesley C

    2009-01-01

    This paper presents the results of collisional evolution calculations for the Kuiper belt starting from an initial size distribution similar to that produced by accretion simulations of that region - a steep power-law large object size distribution that breaks to a shallower slope at r ~1-2 km, with collisional equilibrium achieved for objects r ~0.5 km. We find that the break from the steep large object power-law causes a divot, or depletion of objects at r ~10-20 km, which in-turn greatly reduces the disruption rate of objects with r> 25-50 km, preserving the steep power-law behavior for objects at this size. Our calculations demonstrate that the roll-over observed in the Kuiper belt size distribution is naturally explained as an edge of a divot in the size distribution; the radius at which the size distribution transitions away from the power-law, and the shape of the divot from our simulations are consistent with the size of the observed roll-over, and size distribution for smaller bodies. Both the kink r...

  5. Triggering Sublimation-Driven Activity of Main Belt Comets

    CERN Document Server

    Haghighipour, Nader; Schaefer, Christoph; Speith, Roland; Dvorak, Rudolf

    2016-01-01

    It has been suggested that the comet-like activity of Main Belt Comets are due to the sublimation of sub-surface water-ice that has been exposed as a result of their surfaces being impacted by m-sized bodies. We have examined the viability of this scenario by simulating impacts between m-sized and km-sized objects using a smooth particle hydrodynamics approach. Simulations have been carried out for different values of the impact velocity and impact angle as well as different target material and water-mass fraction. Results indicate that for the range of impact velocities corresponding to those in the asteroid belt, the depth of an impact crater is slightly larger than 10 m suggesting that if the activation of MBCs is due to the sublimation of sub-surface water-ice, this ice has to exist no deeper than a few meters from the surface. Results also show that ice-exposure occurs in the bottom and on the interior surface of impact craters as well as the surface of the target where some of the ejected icy inclusions...

  6. A Method for Determining Sedimentary Micro-Facies Belts Automatically

    Institute of Scientific and Technical Information of China (English)

    Linfu Xue; Qitai Mei; Quan Sun

    2003-01-01

    It is important to understand the distribution of sedimentary facies, especially the distribution of sand body that is the key for oil production and exploration. The secondary oil recovery requires analyzing a great deal of data accumulated within decades of oil field development. At many cases sedimentary micro-facies maps need to be reconstructed and redrawn frequently, which is time-consuming and heavy. This paper presents an integrated approach for determining the distribution of sedimentary micro-facies, tracing the micro-facies boundary, and drawing the map of sedimentary micro-facies belts automatically by computer technique. The approach is based on the division and correlation of strata of multiple wells as well as analysis of sedimentary facies. The approach includes transform, gridding, interpolation, superposing, searching boundary and drawing the map of sedimentary facies belts, and employs the spatial interpolation method and "worm" interpolation method to determine the distribution of sedimentary micro-facies including sand ribbon and/or sand blanket. The computer software developed on the basis of the above principle provides a tool for quick visualization and understanding the distribution of sedimentary micro-facies and reservoir. Satisfied results have been achieveed by applying the technique to the Putaohua Oil Field in Songliao Basin, China.

  7. Accretion in the Early Kuiper Belt; 2, Fragmentation

    CERN Document Server

    Kenyon, S J; Kenyon, Scott J.; Luu, Jane X.

    1999-01-01

    We describe new planetesimal accretion calculations in the Kuiper Belt that include fragmentation and velocity evolution. All models produce two power law cumulative size distributions, N_C propto r^{-q}, with q = 2.5 for radii less than 0.3-3 km and q = 3 for radii exceeding 1-3 km. The power law indices are nearly independent of the initial mass in the annulus, the initial eccentricity of the planetesimal swarm, and the initial size distribution of the planetesimal swarm. The transition between the two power laws moves to larger radii as the initial eccentricity increases. The maximum size of objects depends on their intrinsic tensile strength; Pluto formation requires a strength exceeding 300 erg per gram. Our models yield formation timescales for Pluto-sized objects of 30-40 Myr for a minimum mass solar nebula. The production of several `Plutos' and more than 10^5 50 km radius Kuiper Belt objects leaves most of the initial mass in 0.1-10 km radius objects that can be collisionally depleted over the age of...

  8. Main-Belt Comet P/2012 T1 (PANSTARRS)

    CERN Document Server

    Hsieh, Henry H; Novakovic, Bojan; Yang, Bin; Haghighipour, Nader; Micheli, Marco; Denneau, Larry; Fitzsimmons, Alan; Jedicke, Robert; Kleyna, Jan; Veres, Peter; Wainscoat, Richard J; Ansdell, Megan; Elliott, Garrett T; Keane, Jacqueline V; Meech, Karen J; Moskovitz, Nicholas A; Riesen, Timm E; Sheppard, Scott S; Sonnett, Sarah; Tholen, David J; Urban, Laurie; Kaiser, Nick; Chambers, K C; Burgett, William S; Magnier, Eugene A; Morgan, Jeffrey S; Price, Paul A

    2013-01-01

    We present initial results from observations and numerical analyses aimed at characterizing main-belt comet P/2012 T1 (PANSTARRS). Optical monitoring observations were made between October 2012 and February 2013 using the University of Hawaii 2.2 m telescope, the Keck I telescope, the Baade and Clay Magellan telescopes, Faulkes Telescope South, the Perkins Telescope at Lowell Observatory, and the Southern Astrophysical Research (SOAR) telescope. The object's intrinsic brightness approximately doubles from the time of its discovery in early October until mid-November and then decreases by ~60% between late December and early February, similar to photometric behavior exhibited by several other main-belt comets and unlike that exhibited by disrupted asteroid (596) Scheila. We also used Keck to conduct spectroscopic searches for CN emission as well as absorption at 0.7 microns that could indicate the presence of hydrated minerals, finding an upper limit CN production rate of QCN100 Myr and is unlikely to be a rec...

  9. Ninety five percent: an evaluation of law, policy, and programs to promote seat belt use in Washington state.

    Science.gov (United States)

    Salzberg, Philip M; Moffat, John M

    2004-01-01

    Seat belt use in Washington state was 83% in 2001. In 2002, a series of law, policy, and program initiatives coalesced to produce a dramatic increase in seat belt use. Washington enacted a primary enforcement seat belt, the Chief of the Washington State Patrol made safety belt enforcement one of the core missions of that agency, and Washington participated in the national Memorial Day Click It or Ticket program during May 2002 and continued the program into 2003. Evaluation of these initiatives was accomplished through observation surveys of seat belt use, analysis of seat belt violation data, and analysis of data on traffic deaths of motor vehicle occupants. The major findings were that there was a two- to three-fold increase in enforcement of the seat belt law, belt use rates increased to 93% in 2002 and again to 95% in 2003, and motor-vehicle occupant fatalities decreased by 13%. IMPACT ON PRACTICE AND POLICY: The primary seat belt law and Click It or Ticket program activities were critical factors in increasing belt use in Washington state. Media and enforcement programs targeting seat belt use can be very effective in raising the belt use rate, but a long-term commitment to continuation of these program activities is essential. Other states implementing new primary seat belt laws should consider delivering a Click It or Ticket campaign prior to the effective date of the primary law and continuing these activities during subsequent months and years.

  10. Paleoproterozoic postcollisional magmatic belt of the southern Siberian craton

    Science.gov (United States)

    Salnikova, E. B.; Larin, A. M.; Kotov, A. B.; Levitsky, V. I.; Reznitsky, L. Z.; Kovach, V. P.; Yakovleva, S. Z.

    2003-04-01

    Paleoproterozoic time is characterized by large-scale collisional and postcollisional magmatic activity evidenced in the most of ancient cratons. This global event is related to the Arctic supercontinent assemblage (Rogers, 1996). The formation of postcollisional magmatic belt at 1.9-1.8 Ga within the south-west flanking of the Siberian craton is a remarkable example of these processes happened during overall lithospheric convergence. This belt is extends for about 3000 km from the southern Enisey ridge at the west to the central Aldan shield at the east. Within the central Aldan shield the latest collisional event occurred 1925+/-5 Ma (Kotov et al, 2003) and post-collisional subalkaline S- and I-type granites emplaced at 1916+/-10 Ma (Bibikova et al., 1989), 1901+/-1 Ma (Frost et al., 1998) and 1899+/-6 Ma (Kotov et al, 2003). However at the southern Olekma terrain (western Aldan shield) the syncollisional granites have formed at 1906+/-4 Ma and postcollisional Kodar granitoids were generated at 1876-1873 Ma (Larin et al., 2000). The is a tendency outlined in timing of postcollision processes to the west (in modern coordinates). Ages of postcollisional Kevakta granitoid plutons (1846+/-8 Ma) and volcanics of North-Baikal volcano-plutonic belt (1869+/-6 Ma 1856+/-3 Ma), Baikal folded area, support this tendency. Emplacement of the Primorsky complex postcollisional rapakivi-type granitoids (southern Baikal lake) occurred at 1859+/-16 Ma (Donskaya et al., 2002). New results of U-Pb single zircon and baddeleyite dating demonstrate that formation of late-synkinematic syenite, charnockite and pegmatitic veins (1856±12 Ma, 1853±20 Ma) and calciphyre (1868±2 Ma) within the eastern part of the Sharyzhalgay block (southern Baikal lake) occurred virtually within the same episode. Postcollisional intrusive charnockite of the Shumikha complex from the western Sharyzhalgay block dated at 1861±1 Ma (Donskaya et al., 2001) and 1871±17 Ma (Levitsky et al., 2002). Subalcaline

  11. Archimetrics: a quantitative tool to predict three-dimensional meander belt sandbody heterogeneity

    NARCIS (Netherlands)

    van de Lageweg, Wietse I.|info:eu-repo/dai/nl/32298694X; van Dijk, Wout M.|info:eu-repo/dai/nl/322965330; Box, Darren; Kleinhans, Maarten G.|info:eu-repo/dai/nl/217675123

    Fluvial meander belt sediments form some of the most architecturally complex reservoirs in hydrocarbon fields due to multiple scales of heterogeneity inherent in their deposition. Currently, characterization of meander belt bodies largely relies on idealized vertical profiles and a limited number of

  12. Increasing Seat Belt Use in Service Vehicle Drivers with a Gearshift Delay

    Science.gov (United States)

    Van Houten, Ron; Malenfant, J. E. Louis; Reagan, Ian; Sifrit, Kathy; Compton, Richard

    2010-01-01

    This study evaluated a device that prevents drivers from shifting vehicles into gear for up to 8 s unless seat belts are buckled. Participants were 101 commercial drivers who operated vans, pickups, or other light trucks from the U.S. and Canada. The driver could escape or avoid the delay by fastening his or her seat belt before shifting out of…

  13. Seat Belts in School Buses: A Technical Analysis of the Literature.

    Science.gov (United States)

    Splaine, Pam; Frankel, Steven M.

    This report, prepared for the Montgomery County (Maryland) Public Schools superintendent and board members, identifies the questions concerning seat belt use in school buses, examines relevant literature, and draws some conclusions. According to the literature, seat belts are one of many alternative and interdependent safety devices built into…

  14. 14 CFR 121.317 - Passenger information requirements, smoking prohibitions, and additional seat belt requirements.

    Science.gov (United States)

    2010-01-01

    ... prohibitions, and additional seat belt requirements. 121.317 Section 121.317 Aeronautics and Space FEDERAL... prohibitions, and additional seat belt requirements. (a) Except as provided in paragraph (l) of this section... paragraph (l) of this section, the “Fasten Seat Belt” sign shall be turned on during any movement on...

  15. Seat Belts Don't Save Lives; Trained Drivers and Safe Vehicles Do.

    Science.gov (United States)

    Bernard, Roscoe

    1983-01-01

    Presents five arguments against requiring seat belts on school buses, including the need for better trained drivers, the danger that students will be trapped by seat belts in emergencies, and other problems relating to practicality and cost. Included is an editorial insert indicating how safety advocates respond to such objections. (JBM)

  16. Injury pattern as an indication of seat belt failure in ejected vehicle occupants.

    Science.gov (United States)

    Freeman, Michael D; Eriksson, Anders; Leith, Wendy

    2014-09-01

    Prior authors have suggested that when occupant ejection occurs in association with a seat belt failure, entanglement of the outboard upper extremity (OUE) with the retracting shoulder belt will invariably occur, leaving injury pattern evidence of belt use. In the present investigation, the authors assessed this theory using data accessed from the NASS-CDS for ejected front seat occupants of passenger vehicles. Logistic regression models were used to assess the associations between seat belt failure status and injuries. Injury types associated with seat belt failure were significant OUE and head injuries (OR = 3.87, [95% CI 1.2, 13.0] and 3.1, [95% CI 1.0, 9.7], respectively). The two injury types were found to be a predictor of seat belt use and subsequent failure only if combined with a high (≥0.8) precrash probability of belt use. The injury pattern associated with a seat belt failure-related ejection has limited use in the forensic investigation of crash-related ejections.

  17. A Parametric Energy Model for Energy Management of Long Belt Conveyors

    Directory of Open Access Journals (Sweden)

    Tebello Mathaba

    2015-12-01

    Full Text Available As electricity prices continue to rise, the increasing need for energy management requires better understanding of models for energy-consuming applications, such as conveyor belts. Conveyor belts are used in a wide range of industries, including power generation, mining and mineral processing. Conveyor technological advances are leading to increasingly long conveyor belts being commissioned. Thus, the energy consumption of each individual belt conveyor unit is becoming increasingly significant. This paper proposes a generic energy model for belt conveyors with long troughed belts. The model has a two-parameter power equation, and it uses a partial differential equation to capture the variable amount of material mass per unit length throughout the belt length. Verification results show that the power consumption calculations of the newly proposed simpler model are consistent with those of a known non-linear model with an error of less than 4%. The online parameter identification set-up of the model is proposed. Simulations indicate that the parameters can be identified successfully from data with up to 15% measurement noise. Results show that the proposed model gives better predictions of the power consumed and material delivered by a long conveyor belt than the steady-state models in the current literature.

  18. Thrust Belts and Foreland Basins——SGF/SGE Joint Earth Science Meeting

    Institute of Scientific and Technical Information of China (English)

    Olivier Lacombe; Jér(o)me Lavé; Fran(c)ois Roure

    2006-01-01

    @@ What is the important geologic information that thrust belts and foreland basins have recorded on the erogenic evolution of adjacent mountain belts? How can they reveal the coupled influence of deep (flexure, plate rheology and kinematics) and surficial (erosion, sedimentation) geological processes?

  19. Archimetrics: a quantitative tool to predict three-dimensional meander belt sandbody heterogeneity

    NARCIS (Netherlands)

    van de Lageweg, Wietse I.; van Dijk, Wout M.; Box, Darren; Kleinhans, Maarten G.

    2016-01-01

    Fluvial meander belt sediments form some of the most architecturally complex reservoirs in hydrocarbon fields due to multiple scales of heterogeneity inherent in their deposition. Currently, characterization of meander belt bodies largely relies on idealized vertical profiles and a limited number of

  20. Using Jupiter's Synchrotron Radiation as a Probe into Jupiter's Inner Radiation Belts

    Science.gov (United States)

    Bolton, S. J.; Gulkis, S.; Klein, M. J.; Thorne, R. M.

    1995-01-01

    The Jovian decimetric emission is caused by the combined emission of synchrotron radiation originating from the relativistic electrons trapped in Jupiter's 'Van Allen radiation belts' and thermal emission from the planet's atmosphere. Synchrotron radiation characteristics and variations (which provides insight into the physical properties of Jupiter's inner radiation belts) will be amplified and discussed.